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You Y, Xiao J, Chen J, Li Y, Li R, Zhang S, Jiang Q, Liu P. Integrated Information for Pathogenicity and Treatment of Spiroplasma. Curr Microbiol 2024; 81:252. [PMID: 38953991 DOI: 10.1007/s00284-024-03730-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2023] [Accepted: 05/05/2024] [Indexed: 07/04/2024]
Abstract
Spiroplasma, belonging to the class Mollicutes, is a small, helical, motile bacterium lacking a cell wall. Its host range includes insects, plants, and aquatic crustaceans. Recently, a few human cases of Spiroplasma infection have been reported. The diseases caused by Spiroplasma have brought about serious economic losses and hindered the healthy development of agriculture. The pathogenesis of Spiroplasma involves the ability to adhere, such as through the terminal structure of Spiroplasma, colonization, and invasive enzymes. However, the exact pathogenic mechanism of Spiroplasma remains a mystery. Therefore, we systematically summarize all the information about Spiroplasma in this review article. This provides a reference for future studies on virulence factors and treatment strategies of Spiroplasma.
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Affiliation(s)
- Yixue You
- Institute of Pathogenic Biology, Basic Medical School, Hengyang Medical School, University of South China, Hengyang, 421001, China
| | - Jianmin Xiao
- Institute of Pathogenic Biology, Basic Medical School, Hengyang Medical School, University of South China, Hengyang, 421001, China
| | - Jiaxin Chen
- Institute of Pathogenic Biology, Basic Medical School, Hengyang Medical School, University of South China, Hengyang, 421001, China
| | - Yuxin Li
- Institute of Pathogenic Biology, Basic Medical School, Hengyang Medical School, University of South China, Hengyang, 421001, China
| | - Rong Li
- Institute of Pathogenic Biology, Basic Medical School, Hengyang Medical School, University of South China, Hengyang, 421001, China
| | - Siyuan Zhang
- Institute of Pathogenic Biology, Basic Medical School, Hengyang Medical School, University of South China, Hengyang, 421001, China
- Freshwater Fisheries Research Institute of Jiangsu Province, Nanjing, 210017, China
| | - Qichen Jiang
- Freshwater Fisheries Research Institute of Jiangsu Province, Nanjing, 210017, China.
| | - Peng Liu
- Institute of Pathogenic Biology, Basic Medical School, Hengyang Medical School, University of South China, Hengyang, 421001, China.
- Hunan Provincial Key Laboratory for Special Pathogens Prevention and Control, Institute of Pathogenic Biology, Hengyang Medical College, University of South China, Hengyang, 421001, Hunan, China.
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Sarkar P, Lin CY, Buritica JR, Killiny N, Levy A. Crossing the Gateless Barriers: Factors Involved in the Movement of Circulative Bacteria Within Their Insect Vectors. PHYTOPATHOLOGY 2023; 113:1805-1816. [PMID: 37160668 DOI: 10.1094/phyto-07-22-0249-ia] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/11/2023]
Abstract
Plant bacterial pathogens transmitted by hemipteran vectors pose a large threat to the agricultural industry worldwide. Although virus-vector relationships have been widely investigated, a significant gap exists in our understanding of the molecular interactions between circulative bacteria and their insect vectors, mainly leafhoppers and psyllids. In this review, we will describe how these bacterial pathogens adhere, invade, and proliferate inside their insect vectors. We will also highlight the different transmission routes and molecular factors of phloem-limited bacteria that maintain an effective relationship with the insect host. Understanding the pathogen-vector relationship at the molecular level will help in the management of vector-borne bacterial diseases.
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Affiliation(s)
- Poulami Sarkar
- Citrus Research and Education Center, University of Florida, Lake Alfred, FL 33850
| | - Chun-Yi Lin
- Citrus Research and Education Center, University of Florida, Lake Alfred, FL 33850
| | - Jacobo Robledo Buritica
- Citrus Research and Education Center, University of Florida, Lake Alfred, FL 33850
- Department of Plant Pathology, University of Florida, Gainesville, FL 32611
| | - Nabil Killiny
- Citrus Research and Education Center, University of Florida, Lake Alfred, FL 33850
- Department of Plant Pathology, University of Florida, Gainesville, FL 32611
| | - Amit Levy
- Citrus Research and Education Center, University of Florida, Lake Alfred, FL 33850
- Department of Plant Pathology, University of Florida, Gainesville, FL 32611
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Sagouti T, Belabess Z, Rhallabi N, Barka EA, Tahiri A, Lahlali R. Citrus Stubborn Disease: Current Insights on an Enigmatic Problem Prevailing in Citrus Orchards. Microorganisms 2022; 10:183. [PMID: 35056632 PMCID: PMC8779666 DOI: 10.3390/microorganisms10010183] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2021] [Revised: 01/05/2022] [Accepted: 01/12/2022] [Indexed: 12/29/2022] Open
Abstract
Citrus stubborn was initially observed in California in 1915 and was later proven as a graft-transmissible disease in 1942. In the field, diseased citrus trees have compressed and stunted appearances, and yield poor-quality fruits with little market value. The disease is caused by Spiroplasma citri, a phloem-restricted pathogenic mollicute, which belongs to the Spiroplasmataceae family (Mollicutes). S. citri has the largest genome of any Mollicutes investigated, with a genome size of roughly 1780 Kbp. It is a helical, motile mollicute that lacks a cell wall and peptidoglycan. Several quick and sensitive molecular-based and immuno-enzymatic pathogen detection technologies are available. Infected weeds are the primary source of transmission to citrus, with only a minor percentage of transmission from infected citrus to citrus. Several phloem-feeding leafhopper species (Cicadellidae, Hemiptera) support the natural spread of S. citri in a persistent, propagative manner. S. citri-free buds are used in new orchard plantings and bud certification, and indexing initiatives have been launched. Further, a quarantine system for newly introduced types has been implemented to limit citrus stubborn disease (CSD). The present state of knowledge about CSD around the world is summarized in this overview, where recent advances in S. citri detection, characterization, control and eradication were highlighted to prevent or limit disease spread through the adoption of best practices.
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Affiliation(s)
- Tourya Sagouti
- Laboratoire de Virologie, Microbiologie et Qualité/Ecotoxicologie et Biodiversité, Faculté des Sciences et Techniques de Mohammedia, Mohammedia 20650, Morocco; (T.S.); (N.R.)
| | - Zineb Belabess
- Plant Protection Laboratory, Regional Center of Agricultural Research of Oujda, National Institute of Agricultural Research, Avenue Mohamed VI, BP428 Oujda, Oujda 60000, Morocco;
| | - Naima Rhallabi
- Laboratoire de Virologie, Microbiologie et Qualité/Ecotoxicologie et Biodiversité, Faculté des Sciences et Techniques de Mohammedia, Mohammedia 20650, Morocco; (T.S.); (N.R.)
| | - Essaid Ait Barka
- Unité de Recherche Résistance Induite et Bio-Protection des Plantes-EA 4707, Université de Reims Champagne-Ardenne, 51100 Reims, France
| | - Abdessalem Tahiri
- Phytopathology Unit, Department of Plant Protection, Ecole Nationale d’Agriculture de Meknès, Meknes 50001, Morocco;
| | - Rachid Lahlali
- Phytopathology Unit, Department of Plant Protection, Ecole Nationale d’Agriculture de Meknès, Meknes 50001, Morocco;
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Marra A, Masson F, Lemaitre B. The iron transporter Transferrin 1 mediates homeostasis of the endosymbiotic relationship between Drosophila melanogaster and Spiroplasma poulsonii. MICROLIFE 2021; 2:uqab008. [PMID: 37223258 PMCID: PMC10117857 DOI: 10.1093/femsml/uqab008] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 02/19/2021] [Accepted: 06/23/2021] [Indexed: 05/25/2023]
Abstract
Iron is involved in numerous biological processes in both prokaryotes and eukaryotes and is therefore subject to a tug-of-war between host and microbes upon pathogenic infections. In the fruit fly Drosophila melanogaster, the iron transporter Transferrin 1 (Tsf1) mediates iron relocation from the hemolymph to the fat body upon infection as part of the nutritional immune response. The sequestration of iron in the fat body renders it less available for pathogens, hence limiting their proliferation and enhancing the host ability to fight the infection. Here we investigate the interaction between host iron homeostasis and Spiroplasma poulsonii, a facultative, vertically transmitted, endosymbiont of Drosophila. This low-pathogenicity bacterium is devoid of cell wall and is able to thrive in the host hemolymph without triggering pathogen-responsive canonical immune pathways. However, hemolymph proteomics revealed an enrichment of Tsf1 in infected flies. We find that S. poulsonii induces tsf1 expression and triggers an iron sequestration response similarly to pathogenic bacteria. We next demonstrate that free iron cannot be used by Spiroplasma while Tsf1-bound iron promotes bacterial growth, underlining the adaptation of Spiroplasma to the intra-host lifestyle where iron is mostly protein-bound. Our results show that Tsf1 is used both by the fly to sequester iron and by Spiroplasma to forage host iron, making it a central protein in endosymbiotic homeostasis.
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Affiliation(s)
- Alice Marra
- Global Health Institute, School of Life Sciences, École Polytechnique Fédérale de Lausanne (EPFL), Lausanne, Switzerland
| | - Florent Masson
- Global Health Institute, School of Life Sciences, École Polytechnique Fédérale de Lausanne (EPFL), Lausanne, Switzerland
| | - Bruno Lemaitre
- Global Health Institute, School of Life Sciences, École Polytechnique Fédérale de Lausanne (EPFL), Lausanne, Switzerland
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Rattner R, Thapa SP, Dang T, Osman F, Selvaraj V, Maheshwari Y, Pagliaccia D, Espindola AS, Hajeri S, Chen J, Coaker G, Vidalakis G, Yokomi R. Genome analysis of Spiroplasma citri strains from different host plants and its leafhopper vectors. BMC Genomics 2021; 22:373. [PMID: 34022804 PMCID: PMC8140453 DOI: 10.1186/s12864-021-07637-8] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2020] [Accepted: 04/21/2021] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Spiroplasma citri comprises a bacterial complex that cause diseases in citrus, horseradish, carrot, sesame, and also infects a wide array of ornamental and weed species. S. citri is transmitted in a persistent propagative manner by the beet leafhopper, Neoaliturus tenellus in North America and Circulifer haematoceps in the Mediterranean region. Leafhopper transmission and the pathogen's wide host range serve as drivers of genetic diversity. This diversity was examined in silico by comparing the genome sequences of seven S. citri strains from the United States (BR12, CC-2, C5, C189, LB 319, BLH-13, and BLH-MB) collected from different hosts and times with other publicly available spiroplasmas. RESULTS Phylogenetic analysis using 16S rRNA sequences from 39 spiroplasmas obtained from NCBI database showed that S. citri strains, along with S. kunkelii and S. phoeniceum, two other plant pathogenic spiroplasmas, formed a monophyletic group. To refine genetic relationships among S. citri strains, phylogenetic analyses with 863 core orthologous sequences were performed. Strains that clustered together were: CC-2 and C5; C189 and R8-A2; BR12, BLH-MB, BLH-13 and LB 319. Strain GII3-3X remained in a separate branch. Sequence rearrangements were observed among S. citri strains, predominantly in the center of the chromosome. One to nine plasmids were identified in the seven S. citri strains analyzed in this study. Plasmids were most abundant in strains isolated from the beet leafhopper, followed by strains from carrot, Chinese cabbage, horseradish, and citrus, respectively. All these S. citri strains contained one plasmid with high similarity to plasmid pSci6 from S. citri strain GII3-3X which is known to confer insect transmissibility. Additionally, 17 to 25 prophage-like elements were identified in these genomes, which may promote rearrangements and contribute to repetitive regions. CONCLUSIONS The genome of seven S. citri strains were found to contain a single circularized chromosome, ranging from 1.58 Mbp to 1.74 Mbp and 1597-2232 protein-coding genes. These strains possessed a plasmid similar to pSci6 from the GII3-3X strain associated with leafhopper transmission. Prophage sequences found in the S. citri genomes may contribute to the extension of its host range. These findings increase our understanding of S. citri genetic diversity.
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Affiliation(s)
- Rachel Rattner
- Crop Diseases, Pests, and Genetics Research Unit, San Joaquin Valley Agricultural Sciences Center, USDA Agricultural Research Service, Parlier, CA, 93648, USA
| | - Shree Prasad Thapa
- Department of Plant Pathology, University of California, Davis, CA, 95616, USA
| | - Tyler Dang
- Department of Microbiology and Plant Pathology, University of California, Riverside, CA, 92521, USA
| | - Fatima Osman
- Department of Plant Pathology, University of California, Davis, CA, 95616, USA
| | - Vijayanandraj Selvaraj
- Crop Diseases, Pests, and Genetics Research Unit, San Joaquin Valley Agricultural Sciences Center, USDA Agricultural Research Service, Parlier, CA, 93648, USA
| | - Yogita Maheshwari
- Crop Diseases, Pests, and Genetics Research Unit, San Joaquin Valley Agricultural Sciences Center, USDA Agricultural Research Service, Parlier, CA, 93648, USA
| | - Deborah Pagliaccia
- Department of Microbiology and Plant Pathology, University of California, Riverside, CA, 92521, USA
| | - Andres S Espindola
- Department of Entomology & Plant Pathology and Institute of Biosecurity and Microbial Forensics, Oklahoma State University, Stillwater, OK, 74078, USA
| | - Subhas Hajeri
- Citrus Pest Detection Program, Central California Tristeza Eradication Agency, Tulare, CA, 93274, USA
| | - Jianchi Chen
- Crop Diseases, Pests, and Genetics Research Unit, San Joaquin Valley Agricultural Sciences Center, USDA Agricultural Research Service, Parlier, CA, 93648, USA
| | - Gitta Coaker
- Department of Plant Pathology, University of California, Davis, CA, 95616, USA
| | - Georgios Vidalakis
- Department of Microbiology and Plant Pathology, University of California, Riverside, CA, 92521, USA
| | - Raymond Yokomi
- Crop Diseases, Pests, and Genetics Research Unit, San Joaquin Valley Agricultural Sciences Center, USDA Agricultural Research Service, Parlier, CA, 93648, USA.
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Vera-Ponce León A, Dominguez-Mirazo M, Bustamante-Brito R, Higareda-Alvear V, Rosenblueth M, Martínez-Romero E. Functional genomics of a Spiroplasma associated with the carmine cochineals Dactylopius coccus and Dactylopius opuntiae. BMC Genomics 2021; 22:240. [PMID: 33823812 PMCID: PMC8025503 DOI: 10.1186/s12864-021-07540-2] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2020] [Accepted: 03/18/2021] [Indexed: 02/04/2023] Open
Abstract
BACKGROUND Spiroplasma is a widely distributed endosymbiont of insects, arthropods, and plants. In insects, Spiroplasma colonizes the gut, hemolymph, and reproductive organs of the host. Previous metagenomic surveys of the domesticated carmine cochineal Dactylopius coccus and the wild cochineal D. opuntiae reported sequences of Spiroplasma associated with these insects. However, there is no analysis of the genomic capabilities and the interaction of this Spiroplasma with Dactylopius. RESULTS Here we present three Spiroplasma genomes independently recovered from metagenomes of adult males and females of D. coccus, from two different populations, as well as from adult females of D. opuntiae. Single-copy gene analysis showed that these genomes were > 92% complete. Phylogenomic analyses classified these genomes as new members of Spiroplasma ixodetis. Comparative genome analysis indicated that they exhibit fewer genes involved in amino acid and carbon catabolism compared to other spiroplasmas. Moreover, virulence factor-encoding genes (i.e., glpO, spaid and rip2) were found incomplete in these S. ixodetis genomes. We also detected an enrichment of genes encoding the type IV secretion system (T4SS) in S. ixodetis genomes of Dactylopius. A metratranscriptomic analysis of D. coccus showed that some of these T4SS genes (i.e., traG, virB4 and virD4) in addition to the superoxide dismutase sodA of S. ixodetis were overexpressed in the ovaries. CONCLUSION The symbiont S. ixodetis is a new member of the bacterial community of D. coccus and D. opuntiae. The recovery of incomplete virulence factor-encoding genes in S. ixodetis of Dactylopius suggests that this bacterium is a non-pathogenic symbiont. A high number of genes encoding the T4SS, in the S. ixodetis genomes and the overexpression of these genes in the ovary and hemolymph of the host suggest that S. ixodetis use the T4SS to interact with the Dactylopius cells. Moreover, the transcriptional differences of S. ixodetis among the gut, hemolymph and ovary tissues of D. coccus indicate that this bacterium can respond and adapt to the different conditions (e.g., oxidative stress) present within the host. All this evidence proposes that there is a strong interaction and molecular signaling in the symbiosis between S. ixodetis and the carmine cochineal Dactylopius.
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Affiliation(s)
- Arturo Vera-Ponce León
- Programa de Ecología Genómica, Centro de Ciencias Genómicas, Universidad Nacional Autónoma de México, Cuernavaca, Mexico. .,Present Address: Faculty of Biotechnology, Chemistry and Food Science, Norwegian University of Life Sciences, 1433, Ås, Norway.
| | - Marian Dominguez-Mirazo
- Programa de Ecología Genómica, Centro de Ciencias Genómicas, Universidad Nacional Autónoma de México, Cuernavaca, Mexico.,Present Address: School of Biology, Georgia Institute of Technology, Atlanta, GA, USA
| | - Rafael Bustamante-Brito
- Programa de Ecología Genómica, Centro de Ciencias Genómicas, Universidad Nacional Autónoma de México, Cuernavaca, Mexico
| | - Víctor Higareda-Alvear
- Programa de Ecología Genómica, Centro de Ciencias Genómicas, Universidad Nacional Autónoma de México, Cuernavaca, Mexico
| | - Mónica Rosenblueth
- Programa de Ecología Genómica, Centro de Ciencias Genómicas, Universidad Nacional Autónoma de México, Cuernavaca, Mexico
| | - Esperanza Martínez-Romero
- Programa de Ecología Genómica, Centro de Ciencias Genómicas, Universidad Nacional Autónoma de México, Cuernavaca, Mexico
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Gerth M, Martinez-Montoya H, Ramirez P, Masson F, Griffin JS, Aramayo R, Siozios S, Lemaitre B, Mateos M, Hurst GDD. Rapid molecular evolution of Spiroplasma symbionts of Drosophila. Microb Genom 2021; 7:000503. [PMID: 33591248 PMCID: PMC8208695 DOI: 10.1099/mgen.0.000503] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2020] [Accepted: 01/22/2021] [Indexed: 12/21/2022] Open
Abstract
Spiroplasma is a genus of Mollicutes whose members include plant pathogens, insect pathogens and endosymbionts of animals. Spiroplasma phenotypes have been repeatedly observed to be spontaneously lost in Drosophila cultures, and several studies have documented a high genomic turnover in Spiroplasma symbionts and plant pathogens. These observations suggest that Spiroplasma evolves quickly in comparison to other insect symbionts. Here, we systematically assess evolutionary rates and patterns of Spiroplasma poulsonii, a natural symbiont of Drosophila. We analysed genomic evolution of sHy within flies, and sMel within in vitro culture over several years. We observed that S. poulsonii substitution rates are among the highest reported for any bacteria, and around two orders of magnitude higher compared with other inherited arthropod endosymbionts. The absence of mismatch repair loci mutS and mutL is conserved across Spiroplasma, and likely contributes to elevated substitution rates. Further, the closely related strains sMel and sHy (>99.5 % sequence identity in shared loci) show extensive structural genomic differences, which potentially indicates a higher degree of host adaptation in sHy, a protective symbiont of Drosophila hydei. Finally, comparison across diverse Spiroplasma lineages confirms previous reports of dynamic evolution of toxins, and identifies loci similar to the male-killing toxin Spaid in several Spiroplasma lineages and other endosymbionts. Overall, our results highlight the peculiar nature of Spiroplasma genome evolution, which may explain unusual features of its evolutionary ecology.
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Affiliation(s)
- Michael Gerth
- Institute of Infection, Veterinary and Ecological Sciences, University of Liverpool, Liverpool, UK
- Present address: Department of Biological and Medical Sciences, Oxford Brookes University, Oxford, UK
| | - Humberto Martinez-Montoya
- Laboratorio de Genética y Genómica Comparativa, Unidad Académica Multidisciplinaria Reynosa Aztlán, Universidad Autónoma de Tamaulipas, Reynosa, Mexico
| | - Paulino Ramirez
- Department of Cell Systems and Anatomy, University of Texas Health San Antonio, San Antonio, TX, USA
| | - Florent Masson
- Global Health Institute, School of Life Sciences, Swiss Federal Institute of Technology Lausanne (École Polytechnique Fédérale de Lausanne), Lausanne, Switzerland
| | - Joanne S. Griffin
- Institute of Infection, Veterinary and Ecological Sciences, University of Liverpool, Liverpool, UK
| | - Rodolfo Aramayo
- Department of Biology, Texas A&M University, College Station, TX, USA
| | - Stefanos Siozios
- Institute of Infection, Veterinary and Ecological Sciences, University of Liverpool, Liverpool, UK
| | - Bruno Lemaitre
- Global Health Institute, School of Life Sciences, Swiss Federal Institute of Technology Lausanne (École Polytechnique Fédérale de Lausanne), Lausanne, Switzerland
| | - Mariana Mateos
- Department of Ecology and Conservation Biology, Texas A&M University, College Station, TX, USA
| | - Gregory D. D. Hurst
- Institute of Infection, Veterinary and Ecological Sciences, University of Liverpool, Liverpool, UK
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Chernova OA, Chernov VM, Mouzykantov AA, Baranova NB, Edelstein IA, Aminov RI. Antimicrobial drug resistance mechanisms among Mollicutes. Int J Antimicrob Agents 2020; 57:106253. [PMID: 33264670 DOI: 10.1016/j.ijantimicag.2020.106253] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2019] [Revised: 07/08/2020] [Accepted: 11/22/2020] [Indexed: 12/11/2022]
Abstract
Representatives of the Mollicutes class are the smallest, wall-less bacteria capable of independent reproduction. They are widespread in nature, most are commensals, and some are pathogens of humans, animals and plants. They are also the main contaminants of cell cultures and vaccine preparations. Despite limited biosynthetic capabilities, they are highly adaptable and capable of surviving under various stress and extreme conditions, including antimicrobial selective pressure. This review describes current understanding of antibiotic resistance (ABR) mechanisms in Mollicutes. Protective mechanisms in these bacteria include point mutations, which may include non-target genes, and unique gene exchange mechanisms, contributing to transfer of ABR genes. Better understanding of the mechanisms of emergence and dissemination of ABR in Mollicutes is crucial to control these hypermutable bacteria and prevent the occurrence of highly ABR strains.
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Affiliation(s)
- Olga A Chernova
- Kazan Institute of Biochemistry and Biophysics, FRC Kazan Scientific Centre of RAS, Kazan, Russian Federation
| | - Vladislav M Chernov
- Kazan Institute of Biochemistry and Biophysics, FRC Kazan Scientific Centre of RAS, Kazan, Russian Federation
| | - Alexey A Mouzykantov
- Kazan Institute of Biochemistry and Biophysics, FRC Kazan Scientific Centre of RAS, Kazan, Russian Federation
| | - Natalya B Baranova
- Kazan Institute of Biochemistry and Biophysics, FRC Kazan Scientific Centre of RAS, Kazan, Russian Federation
| | - Inna A Edelstein
- Smolensk State Medical University, Ministry of Health of Russian Federation, Smolensk, Russian Federation
| | - Rustam I Aminov
- School of Medicine, Medical Sciences and Nutrition, University of Aberdeen, Aberdeen, UK; Institute of Fundamental Medicine and Biology, Kazan Federal University, Kazan, Russian Federation.
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Transformation of the Drosophila Sex-Manipulative Endosymbiont Spiroplasma poulsonii and Persisting Hurdles for Functional Genetic Studies. Appl Environ Microbiol 2020; 86:AEM.00835-20. [PMID: 32444468 DOI: 10.1128/aem.00835-20] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2020] [Accepted: 05/12/2020] [Indexed: 01/07/2023] Open
Abstract
Insects are frequently infected by bacterial symbionts that greatly affect their physiology and ecology. Most of these endosymbionts are, however, barely tractable outside their native host, rendering functional genetics studies difficult or impossible. Spiroplasma poulsonii is a facultative bacterial endosymbiont of Drosophila melanogaster that manipulates the reproduction of its host by killing its male progeny at the embryonic stage. S. poulsonii, although a very fastidious bacterium, is closely related to pathogenic Spiroplasma species that are cultivable and genetically modifiable. In this work, we present the transformation of S. poulsonii with a plasmid bearing a fluorescence cassette, leveraging techniques adapted from those used to modify the pathogenic species Spiroplasma citri We demonstrate the feasibility of S. poulsonii transformation and discuss approaches for mutant selection and fly colonization, which are persisting hurdles that must be overcome to allow functional bacterial genetics studies of this endosymbiont in vivo IMPORTANCE Dozens of bacterial endosymbiont species have been described and estimated to infect about half of all insect species. However, only a few them are tractable in vitro, which hampers our understanding of the bacterial determinants of the host-symbiont interaction. Developing a transformation method for S. poulsonii is a major step toward genomic engineering of this symbiont, which will foster basic research on endosymbiosis. This could also open the way to practical uses of endosymbiont engineering through paratransgenesis of vector or pest insects.
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Masson F, Calderon‐Copete S, Schüpfer F, Vigneron A, Rommelaere S, Garcia‐Arraez MG, Paredes JC, Lemaitre B. Blind killing of both male and female Drosophila embryos by a natural variant of the endosymbiotic bacterium Spiroplasma poulsonii. Cell Microbiol 2020; 22:e13156. [PMID: 31912942 PMCID: PMC7187355 DOI: 10.1111/cmi.13156] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2019] [Revised: 12/06/2019] [Accepted: 12/09/2019] [Indexed: 02/07/2023]
Abstract
Spiroplasma poulsonii is a vertically transmitted endosymbiont of Drosophila melanogaster that causes male-killing, that is the death of infected male embryos during embryogenesis. Here, we report a natural variant of S. poulsonii that is efficiently vertically transmitted yet does not selectively kill males, but kills rather a subset of all embryos regardless of their sex, a phenotype we call 'blind-killing'. We show that the natural plasmid of S. poulsonii has an altered structure: Spaid, the gene coding for the male-killing toxin, is deleted in the blind-killing strain, confirming its function as a male-killing factor. Then we further investigate several hypotheses that could explain the sex-independent toxicity of this new strain on host embryos. As the second non-male-killing variant isolated from a male-killing original population, this new strain raises questions on how male-killing is maintained or lost in fly populations. As a natural knock-out of Spaid, which is unachievable yet by genetic engineering approaches, this variant also represents a valuable tool for further investigations on the male-killing mechanism.
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Affiliation(s)
- Florent Masson
- Global Health Institute, School of Life SciencesÉcole Polytechnique Fédérale de Lausanne (EPFL)LausanneSwitzerland
| | - Sandra Calderon‐Copete
- Center for Integrative GenomicsLausanne Genomic Technologies FacilityLausanneSwitzerland
| | - Fanny Schüpfer
- Global Health Institute, School of Life SciencesÉcole Polytechnique Fédérale de Lausanne (EPFL)LausanneSwitzerland
| | - Aurélien Vigneron
- Department of Epidemiology of Microbial DiseasesYale School of Public HealthNew HavenConnecticut
| | - Samuel Rommelaere
- Global Health Institute, School of Life SciencesÉcole Polytechnique Fédérale de Lausanne (EPFL)LausanneSwitzerland
| | - Mario G. Garcia‐Arraez
- Global Health Institute, School of Life SciencesÉcole Polytechnique Fédérale de Lausanne (EPFL)LausanneSwitzerland
| | - Juan C. Paredes
- Global Health Institute, School of Life SciencesÉcole Polytechnique Fédérale de Lausanne (EPFL)LausanneSwitzerland
- Present address:
International Centre of Insect Physiology and Ecology (ICIPE)KasaraniNairobiKenya
| | - Bruno Lemaitre
- Global Health Institute, School of Life SciencesÉcole Polytechnique Fédérale de Lausanne (EPFL)LausanneSwitzerland
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11
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Malembic-Maher S, Desqué D, Khalil D, Salar P, Bergey B, Danet JL, Duret S, Dubrana-Ourabah MP, Beven L, Ember I, Acs Z, Della Bartola M, Materazzi A, Filippin L, Krnjajic S, Krstić O, Toševski I, Lang F, Jarausch B, Kölber M, Jović J, Angelini E, Arricau-Bouvery N, Maixner M, Foissac X. When a Palearctic bacterium meets a Nearctic insect vector: Genetic and ecological insights into the emergence of the grapevine Flavescence dorée epidemics in Europe. PLoS Pathog 2020; 16:e1007967. [PMID: 32210479 PMCID: PMC7135369 DOI: 10.1371/journal.ppat.1007967] [Citation(s) in RCA: 29] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2019] [Revised: 04/06/2020] [Accepted: 02/18/2020] [Indexed: 11/28/2022] Open
Abstract
Flavescence dorée (FD) is a European quarantine grapevine disease transmitted by the Deltocephalinae leafhopper Scaphoideus titanus. Whereas this vector had been introduced from North America, the possible European origin of FD phytoplasma needed to be challenged and correlated with ecological and genetic drivers of FD emergence. For that purpose, a survey of genetic diversity of these phytoplasmas in grapevines, S. titanus, black alders, alder leafhoppers and clematis were conducted in five European countries. Out of 132 map genotypes, only 11 were associated to FD outbreaks, three were detected in clematis, whereas 127 were detected in alder trees, alder leafhoppers or in grapevines out of FD outbreaks. Most of the alder trees were found infected, including 8% with FD genotypes M6, M38 and M50, also present in alders neighboring FD-free vineyards and vineyard-free areas. The Macropsinae Oncopsis alni could transmit genotypes unable to achieve transmission by S. titanus, while the Deltocephalinae Allygus spp. and Orientus ishidae transmitted M38 and M50 that proved to be compatible with S. titanus. Variability of vmpA and vmpB adhesin-like genes clearly discriminated 3 genetic clusters. Cluster Vmp-I grouped genotypes only transmitted by O. alni, while clusters Vmp-II and -III grouped genotypes transmitted by Deltocephalinae leafhoppers. Interestingly, adhesin repeated domains evolved independently in cluster Vmp-I, whereas in clusters Vmp-II and-III showed recent duplications. Latex beads coated with various ratio of VmpA of clusters II and I, showed that cluster II VmpA promoted enhanced adhesion to the Deltocephalinae Euscelidius variegatus epithelial cells and were better retained in both E. variegatus and S. titanus midguts. Our data demonstrate that most FD phytoplasmas are endemic to European alders. Their emergence as grapevine epidemic pathogens appeared restricted to some genetic variants pre-existing in alders, whose compatibility to S. titanus correlates with different vmp gene sequences and VmpA binding properties.
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Affiliation(s)
| | | | - Dima Khalil
- INRAE, Univ. Bordeaux, UMR BFP, Villenave d’Ornon, France
| | - Pascal Salar
- INRAE, Univ. Bordeaux, UMR BFP, Villenave d’Ornon, France
| | - Bernard Bergey
- INRAE, Univ. Bordeaux, UMR BFP, Villenave d’Ornon, France
| | - Jean-Luc Danet
- INRAE, Univ. Bordeaux, UMR BFP, Villenave d’Ornon, France
| | - Sybille Duret
- INRAE, Univ. Bordeaux, UMR BFP, Villenave d’Ornon, France
| | | | - Laure Beven
- INRAE, Univ. Bordeaux, UMR BFP, Villenave d’Ornon, France
| | | | - Zoltan Acs
- Genlogs Biodiagnosztika Ltd, Budapest, Hungary
| | | | - Alberto Materazzi
- Department of Agriculture, Food and Environment, University of Pisa, Pisa, Italy
| | | | - Slobodan Krnjajic
- Department of Plant Pests, Institute of Plant Protection and Environment, Zemun, Serbia
| | - Oliver Krstić
- Department of Plant Pests, Institute of Plant Protection and Environment, Zemun, Serbia
| | - Ivo Toševski
- Department of Plant Pests, Institute of Plant Protection and Environment, Zemun, Serbia
- CABI, Delémont, Switzerland
| | - Friederike Lang
- JKI, Institute for Plant Protection in Fruit Crops and Viticulture, Siebeldingen, Germany
| | - Barbara Jarausch
- JKI, Institute for Plant Protection in Fruit Crops and Viticulture, Siebeldingen, Germany
| | | | - Jelena Jović
- Department of Plant Pests, Institute of Plant Protection and Environment, Zemun, Serbia
| | | | | | - Michael Maixner
- JKI, Institute for Plant Protection in Fruit Crops and Viticulture, Siebeldingen, Germany
| | - Xavier Foissac
- INRAE, Univ. Bordeaux, UMR BFP, Villenave d’Ornon, France
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12
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Abstract
Several lineages of symbiotic bacteria in insects selfishly manipulate host reproduction to spread in a population 1 , often by distorting host sex ratios. Spiroplasma poulsonii2,3 is a helical and motile, Gram-positive symbiotic bacterium that resides in a wide range of Drosophila species 4 . A notable feature of S. poulsonii is male killing, whereby the sons of infected female hosts are selectively killed during development1,2. Although male killing caused by S. poulsonii has been studied since the 1950s, its underlying mechanism is unknown. Here we identify an S. poulsonii protein, designated Spaid, whose expression induces male killing. Overexpression of Spaid in D. melanogaster kills males but not females, and induces massive apoptosis and neural defects, recapitulating the pathology observed in S. poulsonii-infected male embryos5-11. Our data suggest that Spaid targets the dosage compensation machinery on the male X chromosome to mediate its effects. Spaid contains ankyrin repeats and a deubiquitinase domain, which are required for its subcellular localization and activity. Moreover, we found a laboratory mutant strain of S. poulsonii with reduced male-killing ability and a large deletion in the spaid locus. Our study has uncovered a bacterial protein that affects host cellular machinery in a sex-specific way, which is likely to be the long-searched-for factor responsible for S. poulsonii-induced male killing.
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13
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Variable Membrane Protein A of Flavescence Dorée Phytoplasma Binds the Midgut Perimicrovillar Membrane of Euscelidius variegatus and Promotes Adhesion to Its Epithelial Cells. Appl Environ Microbiol 2018; 84:AEM.02487-17. [PMID: 29439985 DOI: 10.1128/aem.02487-17] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2017] [Accepted: 01/30/2018] [Indexed: 01/27/2023] Open
Abstract
Phytoplasmas are uncultivated plant pathogens and cell wall-less bacteria and are transmitted from plant to plant by hemipteran insects. The phytoplasma's circulative propagative cycle in insects requires the crossing of the midgut and salivary glands, and primary adhesion to cells is an initial step toward the invasion process. The flavescence dorée (FD) phytoplasma possesses a set of variable membrane proteins (Vmps) exposed on its surface, and this pathogen is suspected to interact with insect cells. The results showed that VmpA is expressed by the flavescence dorée phytoplasma present in the midgut and salivary glands. Phytoplasmas cannot be cultivated at present, and no mutant can be produced to investigate the putative role of Vmps in the adhesion of phytoplasma to insect cells. To overcome this difficulty, we engineered the Spiroplasma citri mutant G/6, which lacks the ScARP adhesins, for VmpA expression and used VmpA-coated fluorescent beads to determine if VmpA acts as an adhesin in ex vivo adhesion assays and in vivo ingestion assays. VmpA specifically interacted with Euscelidius variegatus insect cells in culture and promoted the retention of VmpA-coated beads to the midgut of E. variegatus In this latest case, VmpA-coated fluorescent beads were localized and embedded in the perimicrovillar membrane of the insect midgut. Thus, VmpA functions as an adhesin that could be essential in the colonization of the insect by the FD phytoplasmas.IMPORTANCE Phytoplasmas infect a wide variety of plants, ranging from wild plants to cultivated species, and are transmitted by different leafhoppers, planthoppers, and psyllids. The specificity of the phytoplasma-insect vector interaction has a major impact on the phytoplasma plant host range. As entry into insect cells is an obligate process for phytoplasma transmission, the bacterial adhesion to insect cells is a key step. Thus, studying surface-exposed proteins of phytoplasma will help to identify the adhesins implicated in the specific recognition of insect vectors. In this study, it is shown that the membrane protein VmpA of the flavescence dorée (FD) phytoplasma acts as an adhesin that is able to interact with cells of Euscelidius variegatus, the experimental vector of the FD phytoplasma.
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14
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In Vitro Culture of the Insect Endosymbiont Spiroplasma poulsonii Highlights Bacterial Genes Involved in Host-Symbiont Interaction. mBio 2018; 9:mBio.00024-18. [PMID: 29559567 PMCID: PMC5874924 DOI: 10.1128/mbio.00024-18] [Citation(s) in RCA: 43] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
Endosymbiotic bacteria associated with eukaryotic hosts are omnipresent in nature, particularly in insects. Studying the bacterial side of host-symbiont interactions is, however, often limited by the unculturability and genetic intractability of the symbionts. Spiroplasma poulsonii is a maternally transmitted bacterial endosymbiont that is naturally associated with several Drosophila species. S. poulsonii strongly affects its host’s physiology, for example by causing male killing or by protecting it against various parasites. Despite intense work on this model since the 1950s, attempts to cultivate endosymbiotic Spiroplasma in vitro have failed so far. Here, we developed a method to sustain the in vitro culture of S. poulsonii by optimizing a commercially accessible medium. We also provide a complete genome assembly, including the first sequence of a natural plasmid of an endosymbiotic Spiroplasma species. Last, by comparing the transcriptome of the in vitro culture to the transcriptome of bacteria extracted from the host, we identified genes putatively involved in host-symbiont interactions. This work provides new opportunities to study the physiology of endosymbiotic Spiroplasma and paves the way to dissect insect-endosymbiont interactions with two genetically tractable partners. The discovery of insect bacterial endosymbionts (maternally transmitted bacteria) has revolutionized the study of insects, suggesting novel strategies for their control. Most endosymbionts are strongly dependent on their host to survive, making them uncultivable in artificial systems and genetically intractable. Spiroplasma poulsonii is an endosymbiont of Drosophila that affects host metabolism, reproduction, and defense against parasites. By providing the first reliable culture medium that allows a long-lasting in vitro culture of Spiroplasma and by elucidating its complete genome, this work lays the foundation for the development of genetic engineering tools to dissect endosymbiosis with two partners amenable to molecular study. Furthermore, the optimization method that we describe can be used on other yet uncultivable symbionts, opening new technical opportunities in the field of host-microbes interactions.
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15
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Infection Function of Adhesin-Like Protein ALP609 from Spiroplasma melliferum CH-1. Curr Microbiol 2018; 75:701-708. [PMID: 29362879 DOI: 10.1007/s00284-018-1435-y] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2017] [Accepted: 01/05/2018] [Indexed: 10/18/2022]
Abstract
Spiroplasma melliferum is the causative agent of spiroplasmosis in honeybees. During infection, adhesion of spiroplasmas to the host cells through adhesion factors is a crucial step. In this study, we identified an adhesin-like protein (ALP609) in S. melliferum CH-1 and investigated its role in the infection. To determine whether ALP609 is an adhesion factor, we performed indirect immunofluorescence microscopy to visualize its adhesion properties. Subsequently, an infection model of S. melliferum CH-1 was established using primary midgut cells of Apis mellifera to examine the adhesion and invasion of spiroplasma using anti-ALP609 antibodies inhibition assays and competition assays with recombinant ALP609 in vitro. We found that anti-ALP609 antibodies could inhibit the adhesion and invasion of spiroplasma to the midgut cells of A. mellifera and reduce midgut cell invasion on increased exposure to recombinant ALP609. To the best of our knowledge, this is the first report identifying adhesion-related factors in S. melliferum. Our results suggested that ALP609 is an adhesin-like protein critical for invasion of S. melliferum CH-1 into midgut cells of A. mellifera.
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16
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Lo WS, Huang YY, Kuo CH. Winding paths to simplicity: genome evolution in facultative insect symbionts. FEMS Microbiol Rev 2018; 40:855-874. [PMID: 28204477 PMCID: PMC5091035 DOI: 10.1093/femsre/fuw028] [Citation(s) in RCA: 72] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Revised: 03/28/2016] [Accepted: 07/10/2016] [Indexed: 02/07/2023] Open
Abstract
Symbiosis between organisms is an important driving force in evolution. Among the diverse relationships described, extensive progress has been made in insect–bacteria symbiosis, which improved our understanding of the genome evolution in host-associated bacteria. Particularly, investigations on several obligate mutualists have pushed the limits of what we know about the minimal genomes for sustaining cellular life. To bridge the gap between those obligate symbionts with extremely reduced genomes and their non-host-restricted ancestors, this review focuses on the recent progress in genome characterization of facultative insect symbionts. Notable cases representing various types and stages of host associations, including those from multiple genera in the family Enterobacteriaceae (class Gammaproteobacteria), Wolbachia (Alphaproteobacteria) and Spiroplasma (Mollicutes), are discussed. Although several general patterns of genome reduction associated with the adoption of symbiotic relationships could be identified, extensive variation was found among these facultative symbionts. These findings are incorporated into the established conceptual frameworks to develop a more detailed evolutionary model for the discussion of possible trajectories. In summary, transitions from facultative to obligate symbiosis do not appear to be a universal one-way street; switches between hosts and lifestyles (e.g. commensalism, parasitism or mutualism) occur frequently and could be facilitated by horizontal gene transfer. This review synthesizes the recent progress in genome characterization of insect-symbiotic bacteria, the emphases include (i) patterns of genome organization, (ii) evolutionary models and trajectories, and (iii) comparisons between facultative and obligate symbionts.
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Affiliation(s)
- Wen-Sui Lo
- Institute of Plant and Microbial Biology, Academia Sinica, Taipei, Taiwan.,Molecular and Biological Agricultural Sciences Program, Taiwan International Graduate Program, National Chung Hsing University and Academia Sinica, Taipei 11529, Taiwan.,Graduate Institute of Biotechnology, National Chung Hsing University, Taichung, Taiwan
| | - Ya-Yi Huang
- Institute of Plant and Microbial Biology, Academia Sinica, Taipei, Taiwan
| | - Chih-Horng Kuo
- Institute of Plant and Microbial Biology, Academia Sinica, Taipei, Taiwan.,Molecular and Biological Agricultural Sciences Program, Taiwan International Graduate Program, National Chung Hsing University and Academia Sinica, Taipei 11529, Taiwan.,Graduate Institute of Biotechnology, National Chung Hsing University, Taichung, Taiwan
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17
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Bendix C, Lewis JD. The enemy within: phloem-limited pathogens. MOLECULAR PLANT PATHOLOGY 2018; 19:238-254. [PMID: 27997761 PMCID: PMC6638166 DOI: 10.1111/mpp.12526] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/27/2016] [Revised: 12/06/2016] [Accepted: 12/08/2016] [Indexed: 05/06/2023]
Abstract
The growing impact of phloem-limited pathogens on high-value crops has led to a renewed interest in understanding how they cause disease. Although these pathogens cause substantial crop losses, many are poorly characterized. In this review, we present examples of phloem-limited pathogens that include intracellular bacteria with and without cell walls, and viruses. Phloem-limited pathogens have small genomes and lack many genes required for core metabolic processes, which is, in part, an adaptation to the unique phloem environment. For each pathogen class, we present multiple case studies to highlight aspects of disease caused by phloem-limited pathogens. The pathogens presented include Candidatus Liberibacter asiaticus (citrus greening), Arsenophonus bacteria, Serratia marcescens (cucurbit yellow vine disease), Candidatus Phytoplasma asteris (Aster Yellows Witches' Broom), Spiroplasma kunkelii, Potato leafroll virus and Citrus tristeza virus. We focus on commonalities in the virulence strategies of these pathogens, and aim to stimulate new discussions in the hope that widely applicable disease management strategies can be found.
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Affiliation(s)
- Claire Bendix
- United States Department of AgriculturePlant Gene Expression CenterAlbanyCA94710USA
| | - Jennifer D. Lewis
- United States Department of AgriculturePlant Gene Expression CenterAlbanyCA94710USA
- Department of Plant and Microbial BiologyUniversity of California, BerkeleyBerkeleyCA94720USA
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18
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Dubrana MP, Guéguéniat J, Bertin C, Duret S, Arricau-Bouvery N, Claverol S, Lartigue C, Blanchard A, Renaudin J, Béven L. Proteolytic Post-Translational Processing of Adhesins in a Pathogenic Bacterium. J Mol Biol 2017; 429:1889-1902. [PMID: 28501585 DOI: 10.1016/j.jmb.2017.05.004] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2017] [Revised: 04/25/2017] [Accepted: 05/04/2017] [Indexed: 11/29/2022]
Abstract
Mollicutes, including mycoplasmas and spiroplasmas, have been considered as good representatives of the « minimal cell » concept: these wall-less bacteria are small in size and possess a minimal genome and restricted metabolic capacities. However, the recent discovery of the presence of post-translational modifications unknown so far, such as the targeted processing of membrane proteins of mycoplasma pathogens for human and swine, revealed a part of the hidden complexity of these microorganisms. In this study, we show that in the phytopathogen, insect-vectored Spiroplasma citri GII-3 adhesion-related protein (ScARP) adhesins are post-translationally processed through an ATP-dependent targeted cleavage. The cleavage efficiency could be enhanced in vitro when decreasing the extracellular pH or upon the addition of polyclonal antibodies directed against ScARP repeated units, suggesting that modification of the surface charge and/or ScARP conformational changes could initiate the cleavage. The two major sites for primary cleavage are localized within predicted disordered regions and do not fit any previously reported cleavage motif; in addition, the inhibition profile and the metal ion requirements indicate that this post-translational modification involves at least one non-conventional protease. Such a proteolytic process may play a role in S. citri colonization of cells of the host insect. Furthermore, our work indicates that post-translational cleavage of adhesins represents a common feature to mollicutes colonizing distinct hosts and that processing of surface antigens could represent a way to make the most out of a minimal genome.
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Affiliation(s)
| | - Julia Guéguéniat
- UMR BFP 1332, Univ. Bordeaux, INRA, Villenave d'Ornon, 33882 France
| | - Clothilde Bertin
- UMR BFP 1332, Univ. Bordeaux, INRA, Villenave d'Ornon, 33882 France
| | - Sybille Duret
- UMR BFP 1332, Univ. Bordeaux, INRA, Villenave d'Ornon, 33882 France
| | | | | | - Carole Lartigue
- UMR BFP 1332, Univ. Bordeaux, INRA, Villenave d'Ornon, 33882 France
| | - Alain Blanchard
- UMR BFP 1332, Univ. Bordeaux, INRA, Villenave d'Ornon, 33882 France
| | - Joël Renaudin
- UMR BFP 1332, Univ. Bordeaux, INRA, Villenave d'Ornon, 33882 France
| | - Laure Béven
- UMR BFP 1332, Univ. Bordeaux, INRA, Villenave d'Ornon, 33882 France.
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19
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Navas LE, Amadio AF, Ortiz EM, Sauka DH, Benintende GB, Berretta MF, Zandomeni RO. Complete Sequence and Organization of pFR260, the Bacillus thuringiensis INTA Fr7-4 Plasmid Harboring Insecticidal Genes. J Mol Microbiol Biotechnol 2017; 27:43-54. [DOI: 10.1159/000451056] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2016] [Accepted: 09/23/2016] [Indexed: 11/19/2022] Open
Abstract
We report the complete sequence and analysis of pFR260, a novel megaplasmid of 260,595 bp from the <i>Bacillus thuringiensis</i> strain INTA Fr7-4 isolated in Argentina. It carries 7 insecticidal genes: 3 <i>cry8</i> copies previously reported, 2 <i>vip1,</i> and 2 <i>vip2</i>. Also, it carries a gene encoding a putative atypical Cry protein. These genes are arranged in a region of approximately 105 kbp in size with characteristics of a pathogenicity island with a potential coleopteran-specific insecticide profile. DNA strand composition asymmetry, as determined by GC skew analysis, and the presence of a Rep protein involved in the initiation of replication suggest a bidirectional <i>theta</i> mechanism of replication. In addition, many genes involved in conjugation and a CRISPR-Cas system were detected. The pFR260 sequence was deposited in GenBank under accession number KX258624.
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20
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Stubborn Disease in Iran: Diversity of Spiroplasma citri Strains in Circulifer haematoceps Leafhoppers Collected in Sesame Fields in Fars Province. Curr Microbiol 2016; 74:239-246. [PMID: 27995305 DOI: 10.1007/s00284-016-1180-z] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2016] [Accepted: 12/08/2016] [Indexed: 10/20/2022]
Abstract
Spiroplasma citri is a bacterial pathogen responsible for the economically important citrus stubborn disease. Sesame and citrus seeds serve as hosts for both S. citri and its leafhopper vector Circulifer haematoceps. To evaluate whether sesame could act as a reservoir for citrus-infecting strains or not, the genetic diversity among S. citri strains found in leafhoppers collected in citrus and citrus-free sesame fields was investigated. Among 26 periwinkle plants exposed to the collected C. haematoceps leafhoppers, 12 plants developed typical stubborn symptoms. All symptomatic periwinkles were polymerase chain reaction positive using S. citri-specific primer pairs targeting the spiralin and P89 genes. Phylogenetic trees based on spiralin gene sequence analysis indicated that the novel field-collected strains clustered with those belonging to two formerly defined S. citri groups (groups 6 and 1). In addition, our results strongly suggest that group 1 strains could be transmitted from sesame-infected plants to citrus trees by C. haematoceps, while group 6 strains may not infect citrus trees.
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21
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Deciphering Clostridium tyrobutyricum Metabolism Based on the Whole-Genome Sequence and Proteome Analyses. mBio 2016; 7:mBio.00743-16. [PMID: 27302759 PMCID: PMC4916380 DOI: 10.1128/mbio.00743-16] [Citation(s) in RCA: 56] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
UNLABELLED Clostridium tyrobutyricum is a Gram-positive anaerobic bacterium that efficiently produces butyric acid and is considered a promising host for anaerobic production of bulk chemicals. Due to limited knowledge on the genetic and metabolic characteristics of this strain, however, little progress has been made in metabolic engineering of this strain. Here we report the complete genome sequence of C. tyrobutyricum KCTC 5387 (ATCC 25755), which consists of a 3.07-Mbp chromosome and a 63-kbp plasmid. The results of genomic analyses suggested that C. tyrobutyricum produces butyrate from butyryl-coenzyme A (butyryl-CoA) through acetate reassimilation by CoA transferase, differently from Clostridium acetobutylicum, which uses the phosphotransbutyrylase-butyrate kinase pathway; this was validated by reverse transcription-PCR (RT-PCR) of related genes, protein expression levels, in vitro CoA transferase assay, and fed-batch fermentation. In addition, the changes in protein expression levels during the course of batch fermentations on glucose were examined by shotgun proteomics. Unlike C. acetobutylicum, the expression levels of proteins involved in glycolytic and fermentative pathways in C. tyrobutyricum did not decrease even at the stationary phase. Proteins related to energy conservation mechanisms, including Rnf complex, NfnAB, and pyruvate-phosphate dikinase that are absent in C. acetobutylicum, were identified. Such features explain why this organism can produce butyric acid to a much higher titer and better tolerate toxic metabolites. This study presenting the complete genome sequence, global protein expression profiles, and genome-based metabolic characteristics during the batch fermentation of C. tyrobutyricum will be valuable in designing strategies for metabolic engineering of this strain. IMPORTANCE Bio-based production of chemicals from renewable biomass has become increasingly important due to our concerns on climate change and other environmental problems. C. tyrobutyricum has been used for efficient butyric acid production. In order to further increase the performance and expand the capabilities of this strain toward production of other chemicals, metabolic engineering needs to be performed. For this, better understanding on the metabolic and physiological characteristics of this bacterium at the genome level is needed. This work reporting the results of complete genomic and proteomic analyses together with new insights on butyric acid biosynthetic pathway and energy conservation will allow development of strategies for metabolic engineering of C. tyrobutyricum for the bio-based production of various chemicals in addition to butyric acid.
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22
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Dubrana MP, Béven L, Arricau-Bouvery N, Duret S, Claverol S, Renaudin J, Saillard C. Differential expression of Spiroplasma citri surface protein genes in the plant and insect hosts. BMC Microbiol 2016; 16:53. [PMID: 27005573 PMCID: PMC4804543 DOI: 10.1186/s12866-016-0666-y] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2015] [Accepted: 03/07/2016] [Indexed: 11/10/2022] Open
Abstract
Background Spiroplasma citri is a cell wall-less, plant pathogenic bacteria that colonizes two distinct hosts, the leafhopper vector and the host plant. Given the absence of a cell wall, surface proteins including lipoproteins and transmembrane polypeptides are expected to play key roles in spiroplasma/host interactions. Important functions in spiroplasma/insect interactions have been shown for a few surface proteins such as the major lipoprotein spiralin, the transmembrane S. citri adhesion-related proteins (ScARPs) and the sugar transporter subunit Sc76. S. citri efficient transmission from the insect to the plant is expected to rely on its ability to adapt to the different environments and more specifically to regulate the expression of genes encoding surface-exposed proteins. Results Genes encoding S. citri lipoproteins and ScARPs were investigated for their expression level in axenic medium, in the leafhopper vector Circulifer haematoceps and in the host plant (periwinkle Catharanthus roseus) either insect-infected or graft-inoculated. The vast majority of the lipoprotein genes tested (25/28) differentially responded to the various host environments. Considering their relative expression levels in the different environments, the possible involvement of the targeted genes in spiroplasma host adaptation was discussed. In addition, two S. citri strains differing notably in their ability to express adhesin ScARP2b and pyruvate dehydrogenase E1 component differed in their capacity to multiply in the two hosts, the plant and the leafhopper vector. Conclusions This study provided us with a list of genes differentially expressed in the different hosts, leading to the identification of factors that are thought to be involved in the process of S. citri host adaptation. The identification of such factors is a key step for further understanding of S. citri pathogenesis. Moreover the present work highlights the high capacity of S. citri in tightly regulating the expression level of a large set of surface protein genes, despite the small size of its genome. Electronic supplementary material The online version of this article (doi:10.1186/s12866-016-0666-y) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Marie-Pierre Dubrana
- UMR 1332 Biologie du Fruit et Pathologie, INRA, F-33882, Villenave d'Ornon, France.,UMR 1332 Biologie du Fruit et Pathologie, Université de Bordeaux, F-33882, Villenave d'Ornon, France
| | - Laure Béven
- UMR 1332 Biologie du Fruit et Pathologie, INRA, F-33882, Villenave d'Ornon, France. .,UMR 1332 Biologie du Fruit et Pathologie, Université de Bordeaux, F-33882, Villenave d'Ornon, France.
| | - Nathalie Arricau-Bouvery
- UMR 1332 Biologie du Fruit et Pathologie, INRA, F-33882, Villenave d'Ornon, France.,UMR 1332 Biologie du Fruit et Pathologie, Université de Bordeaux, F-33882, Villenave d'Ornon, France
| | - Sybille Duret
- UMR 1332 Biologie du Fruit et Pathologie, INRA, F-33882, Villenave d'Ornon, France.,UMR 1332 Biologie du Fruit et Pathologie, Université de Bordeaux, F-33882, Villenave d'Ornon, France
| | - Stéphane Claverol
- Plateforme Protéome, CGFB, Université de Bordeaux, F-33076, Bordeaux, France
| | - Joël Renaudin
- UMR 1332 Biologie du Fruit et Pathologie, INRA, F-33882, Villenave d'Ornon, France.,UMR 1332 Biologie du Fruit et Pathologie, Université de Bordeaux, F-33882, Villenave d'Ornon, France
| | - Colette Saillard
- UMR 1332 Biologie du Fruit et Pathologie, INRA, F-33882, Villenave d'Ornon, France.,UMR 1332 Biologie du Fruit et Pathologie, Université de Bordeaux, F-33882, Villenave d'Ornon, France
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Lo WS, Gasparich GE, Kuo CH. Found and Lost: The Fates of Horizontally Acquired Genes in Arthropod-Symbiotic Spiroplasma. Genome Biol Evol 2015; 7:2458-72. [PMID: 26254485 PMCID: PMC4607517 DOI: 10.1093/gbe/evv160] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Horizontal gene transfer (HGT) is an important mechanism that contributed to biological diversity, particularly in bacteria. Through acquisition of novel genes, the recipient cell may change its ecological preference and the process could promote speciation. In this study, we determined the complete genome sequence of two Spiroplasma species for comparative analyses and inferred the putative gene gains and losses. Although most Spiroplasma species are symbionts of terrestrial insects, Spiroplasma eriocheiris has evolved to be a lethal pathogen of freshwater crustaceans. We found that approximately 7% of the genes in this genome may have originated from HGT and these genes expanded the metabolic capacity of this organism. Through comparison with the closely related Spiroplasma atrichopogonis, as well as other more divergent lineages, our results indicated that these HGT events could be traced back to the most recent common ancestor of these two species. However, most of these horizontally acquired genes have been pseudogenized in S. atrichopogonis, suggesting that they did not contribute to the fitness of this lineage that maintained the association with terrestrial insects. Thus, accumulation of small deletions that disrupted these foreign genes was not countered by natural selection. On the other hand, the long-term survival of these horizontally acquired genes in the S. eriocheiris genome hinted that they might play a role in the ecological shift of this species. Finally, the implications of these findings and the conflicts among gene content, 16S rRNA gene sequencing, and serological typing, are discussed in light of defining bacterial species.
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Affiliation(s)
- Wen-Sui Lo
- Institute of Plant and Microbial Biology, Academia Sinica, Taipei, Taiwan Molecular and Biological Agricultural Sciences Program, Taiwan International Graduate Program, NationalChung Hsing University and Academia Sinica, Taipei, Taiwan Graduate Institute of Biotechnology, National Chung Hsing University, Taichung, Taiwan
| | | | - Chih-Horng Kuo
- Institute of Plant and Microbial Biology, Academia Sinica, Taipei, Taiwan Molecular and Biological Agricultural Sciences Program, Taiwan International Graduate Program, NationalChung Hsing University and Academia Sinica, Taipei, Taiwan Biotechnology Center, National Chung Hsing University, Taichung, Taiwan
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24
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Renaudin J, Béven L, Batailler B, Duret S, Desqué D, Arricau-Bouvery N, Malembic-Maher S, Foissac X. Heterologous expression and processing of the flavescence dorée phytoplasma variable membrane protein VmpA in Spiroplasma citri. BMC Microbiol 2015; 15:82. [PMID: 25879952 PMCID: PMC4392738 DOI: 10.1186/s12866-015-0417-5] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2014] [Accepted: 03/18/2015] [Indexed: 11/21/2022] Open
Abstract
Background Flavescence dorée (FD) of grapevine is a phloem bacterial disease that threatens European vineyards. The disease is associated with a non-cultivable mollicute, a phytoplasma that is transmitted by the grapevine leafhopper Scaphoideus titanus in a persistent, propagative manner. The specificity of insect transmission is presumably mediated through interactions between the host tissues and phytoplasma surface proteins comprising the so-called variable membrane proteins (Vmps). Plant spiroplasmas and phytoplasmas share the same ecological niches, the phloem sieve elements of host plants and the hemocoel of insect vectors. Unlike phytoplasmas, however, spiroplasmas, and Spiroplasma citri in particular, can be grown in cell-free media and genetically engineered. As a new approach for studying phytoplasmas-insect cell interactions, we sought to mimic phytoplasmas through the construction of recombinant spiroplasmas exhibiting FD phytoplasma Vmps at the cell surface. Results Here, we report the expression of the FD phytoplasma VmpA in S. citri. Transformation of S. citri with plasmid vectors in which the vmpA coding sequence was under the control of the S. citri tuf gene promoter resulted in higher accumulation of VmpA than with the native promoter. Expression of VmpA at the spiroplasma surface was achieved by fusing the vmpA coding sequence to the signal peptide sequence of the S. citri adhesin ScARP3d, as revealed by direct colony immunoblotting and immunogold labelling electron microscopy. Anchoring of VmpA to the spiroplasma membrane was further demonstrated by Triton X-114 protein partitioning and Western immunoblotting. Using the same strategy, the secretion of free, functionally active β-lactamase (used as a model protein) into the culture medium by recombinant spiroplasmas was achieved. Conclusions Construction of recombinant spiroplasmas harbouring the FD phytoplasma variable membrane protein VmpA at their surface was achieved, which provides a new biological approach for studying interactions of phytoplasma surface proteins with host cells. Likewise, the secretion of functional β-lactamase by recombinant spiroplasmas established the considerable promise of the S. citri expression system for delivering phytoplasma effector proteins into host cells. Electronic supplementary material The online version of this article (doi:10.1186/s12866-015-0417-5) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Joël Renaudin
- INRA, UMR 1332 Biologie du Fruit et Pathologie, Villenave d'Ornon, France. .,Université de Bordeaux, UMR 1332 Biologie du Fruit et Pathologie, Villenave d'Ornon, France.
| | - Laure Béven
- INRA, UMR 1332 Biologie du Fruit et Pathologie, Villenave d'Ornon, France. .,Université de Bordeaux, UMR 1332 Biologie du Fruit et Pathologie, Villenave d'Ornon, France.
| | - Brigitte Batailler
- INRA, UMR 1332 Biologie du Fruit et Pathologie, Villenave d'Ornon, France. .,Université de Bordeaux, UMR 1332 Biologie du Fruit et Pathologie, Villenave d'Ornon, France. .,Université de Bordeaux, UMS3420, Bordeaux Imaging Center, Bordeaux, France. .,CNRS, Bordeaux Imaging Center, UMS 3420, Bordeaux, France. .,INSERM, Bordeaux Imaging Center, US 004, Bordeaux, France.
| | - Sybille Duret
- INRA, UMR 1332 Biologie du Fruit et Pathologie, Villenave d'Ornon, France. .,Université de Bordeaux, UMR 1332 Biologie du Fruit et Pathologie, Villenave d'Ornon, France.
| | - Delphine Desqué
- INRA, UMR 1332 Biologie du Fruit et Pathologie, Villenave d'Ornon, France. .,Université de Bordeaux, UMR 1332 Biologie du Fruit et Pathologie, Villenave d'Ornon, France.
| | - Nathalie Arricau-Bouvery
- INRA, UMR 1332 Biologie du Fruit et Pathologie, Villenave d'Ornon, France. .,Université de Bordeaux, UMR 1332 Biologie du Fruit et Pathologie, Villenave d'Ornon, France.
| | - Sylvie Malembic-Maher
- INRA, UMR 1332 Biologie du Fruit et Pathologie, Villenave d'Ornon, France. .,Université de Bordeaux, UMR 1332 Biologie du Fruit et Pathologie, Villenave d'Ornon, France.
| | - Xavier Foissac
- INRA, UMR 1332 Biologie du Fruit et Pathologie, Villenave d'Ornon, France. .,Université de Bordeaux, UMR 1332 Biologie du Fruit et Pathologie, Villenave d'Ornon, France.
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25
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Genome sequence of the Drosophila melanogaster male-killing Spiroplasma strain MSRO endosymbiont. mBio 2015; 6:mBio.02437-14. [PMID: 25827421 PMCID: PMC4453565 DOI: 10.1128/mbio.02437-14] [Citation(s) in RCA: 55] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Spiroplasmas are helical and motile members of a cell wall-less eubacterial group called Mollicutes. Although all spiroplasmas are associated with arthropods, they exhibit great diversity with respect to both their modes of transmission and their effects on their hosts; ranging from horizontally transmitted pathogens and commensals to endosymbionts that are transmitted transovarially (i.e., from mother to offspring). Here we provide the first genome sequence, along with proteomic validation, of an endosymbiotic inherited Spiroplasma bacterium, the Spiroplasma poulsonii MSRO strain harbored by Drosophila melanogaster. Comparison of the genome content of S. poulsonii with that of horizontally transmitted spiroplasmas indicates that S. poulsonii has lost many metabolic pathways and transporters, demonstrating a high level of interdependence with its insect host. Consistent with genome analysis, experimental studies showed that S. poulsonii metabolizes glucose but not trehalose. Notably, trehalose is more abundant than glucose in Drosophila hemolymph, and the inability to metabolize trehalose may prevent S. poulsonii from overproliferating. Our study identifies putative virulence genes, notably, those for a chitinase, the H2O2-producing glycerol-3-phosphate oxidase, and enzymes involved in the synthesis of the eukaryote-toxic lipid cardiolipin. S. poulsonii also expresses on the cell membrane one functional adhesion-related protein and two divergent spiralin proteins that have been implicated in insect cell invasion in other spiroplasmas. These lipoproteins may be involved in the colonization of the Drosophila germ line, ensuring S. poulsonii vertical transmission. The S. poulsonii genome is a valuable resource to explore the mechanisms of male killing and symbiont-mediated protection, two cardinal features of many facultative endosymbionts. Most insect species, including important disease vectors and crop pests, harbor vertically transmitted endosymbiotic bacteria. These endosymbionts play key roles in their hosts’ fitness, including protecting them against natural enemies and manipulating their reproduction in ways that increase the frequency of symbiont infection. Little is known about the molecular mechanisms that underlie these processes. Here, we provide the first genome draft of a vertically transmitted male-killing Spiroplasma bacterium, the S. poulsonii MSRO strain harbored by D. melanogaster. Analysis of the S. poulsonii genome was complemented by proteomics and ex vivo metabolic experiments. Our results indicate that S. poulsonii has reduced metabolic capabilities and expresses divergent membrane lipoproteins and potential virulence factors that likely participate in Spiroplasma-host interactions. This work fills a gap in our knowledge of insect endosymbionts and provides tools with which to decipher the interaction between Spiroplasma bacteria and their well-characterized host D. melanogaster, which is emerging as a model of endosymbiosis.
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26
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Wang X, Doddapaneni H, Chen J, Yokomi RK. Improved Real-Time PCR Diagnosis of Citrus Stubborn Disease by Targeting Prophage Genes of Spiroplasma citri. PLANT DISEASE 2015; 99:149-154. [PMID: 30699732 DOI: 10.1094/pdis-06-14-0572-re] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
Spiroplasma citri is a phloem-limited bacterium causing citrus stubborn disease (CSD). Isolation and culturing of S. citri is technically demanding and time consuming. S. citri is typically low in titer and unevenly distributed in citrus, making reliable detection challenging. The current preferred detection method is polymerase chain reaction (PCR) assays with primers developed from sequences of S. citri housekeeping genes. Recent genome sequencing of S. citri revealed that the bacterium harbors multiple copies of prophage genes. Therefore, targeting multicopy prophage genes was hypothesized to improve sensitivity of PCR detection. Two primer sets, Php-orf1 and Php-orf3, were developed from conserved prophage sequences in the S. citri genome. These primer sets were used to evaluate detection sensitivity in SYBR Green-based quantitative PCR (qPCR) assays with 18 S. citri in cultures isolated from different hosts and locations. Prophage primer set Php-orf1 increased detection sensitivity by 4.91 and 3.65 cycle threshold (Cq) units compared with housekeeping gene primers for spiralin and P58 putative adhesin gene, respectively. Detection was slightly less sensitive for the Php-orf3 primer set at 3.02 and 1.76 Cq units, respectively, over the same housekeeping gene primers. The prophage primer sets were validated for qPCR detection with field samples from three citrus orchards in California's San Joaquin Valley collected from 2007 to 2013. The data showed that S. citri prophage sequences improved sensitivity for qPCR detection of S. citri-infected trees at least 10-fold and reduced the number of false-negative results. No false-positive samples were detected with any of the primer sets. The enhanced sensitivity resulted from the higher copy number of prophage genes in the S. citri genome and, thus, improved CSD diagnosis from field samples.
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Affiliation(s)
- Xuefeng Wang
- National Citrus Engineering Research Center, Citrus Research Institute, Southwest University, Chongqing 400712, P. R. China
| | | | - Jianchi Chen
- United States Department of Agriculture-Agricultural Research Service (USDA-ARS), San Joaquin Valley Agricultural Sciences Center, Parlier, CA 93648-9757
| | - Raymond K Yokomi
- United States Department of Agriculture-Agricultural Research Service (USDA-ARS), San Joaquin Valley Agricultural Sciences Center, Parlier, CA 93648-9757
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27
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Bolaños LM, Servín-Garcidueñas LE, Martínez-Romero E. Arthropod-Spiroplasma relationship in the genomic era. FEMS Microbiol Ecol 2014; 91:1-8. [PMID: 25764543 DOI: 10.1093/femsec/fiu008] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023] Open
Abstract
The genus Spiroplasma comprises wall-less, low-GC bacteria that establish pathogenic, mutualistic and commensal symbiotic associations with arthropods and plants. This review focuses on the symbiotic relationships between Spiroplasma bacteria and arthropod hosts in the context of the available genomic sequences. Spiroplasma genomes are reduced and some contain highly repetitive plectrovirus-related sequences. Spiroplasma's diversity in viral invasion susceptibility, virulence factors, substrate utilization, genome dynamics and symbiotic associations with arthropods make this bacterial genus a biological model that provides insights about the evolutionary traits that shape bacterial symbiotic relationships with eukaryotes.
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Affiliation(s)
- Luis M Bolaños
- Centro de Ciencias Genómicas, Universidad Nacional Autónoma de México, Cuernavaca, Morelos 62210, México
| | - Luis E Servín-Garcidueñas
- Centro de Ciencias Genómicas, Universidad Nacional Autónoma de México, Cuernavaca, Morelos 62210, México
| | - Esperanza Martínez-Romero
- Centro de Ciencias Genómicas, Universidad Nacional Autónoma de México, Cuernavaca, Morelos 62210, México
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28
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Scientific Opinion on the pest categorisation of Spiroplasma citri. EFSA J 2014. [DOI: 10.2903/j.efsa.2015.3925] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
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29
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Trachtenberg S, Schuck P, Phillips TM, Andrews SB, Leapman RD. A structural framework for a near-minimal form of life: mass and compositional analysis of the helical mollicute Spiroplasma melliferum BC3. PLoS One 2014; 9:e87921. [PMID: 24586297 PMCID: PMC3931623 DOI: 10.1371/journal.pone.0087921] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2013] [Accepted: 01/01/2014] [Indexed: 12/31/2022] Open
Abstract
Spiroplasma melliferum is a wall-less bacterium with dynamic helical geometry. This organism is geometrically well defined and internally well ordered, and has an exceedingly small genome. Individual cells are chemotactic, polar, and swim actively. Their dynamic helicity can be traced at the molecular level to a highly ordered linear motor (composed essentially of the proteins fib and MreB) that is positioned on a defined helical line along the internal face of the cell's membrane. Using an array of complementary, informationally overlapping approaches, we have taken advantage of this uniquely simple, near-minimal life-form and its helical geometry to analyze the copy numbers of Spiroplasma's essential parts, as well as to elucidate how these components are spatially organized to subserve the whole living cell. Scanning transmission electron microscopy (STEM) was used to measure the mass-per-length and mass-per-area of whole cells, membrane fractions, intact cytoskeletons and cytoskeletal components. These local data were fit into whole-cell geometric parameters determined by a variety of light microscopy modalities. Hydrodynamic data obtained by analytical ultracentrifugation allowed computation of the hydration state of whole living cells, for which the relative amounts of protein, lipid, carbohydrate, DNA, and RNA were also estimated analytically. Finally, ribosome and RNA content, genome size and gene expression were also estimated (using stereology, spectroscopy and 2D-gel analysis, respectively). Taken together, the results provide a general framework for a minimal inventory and arrangement of the major cellular components needed to support life.
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Affiliation(s)
- Shlomo Trachtenberg
- Dept of Microbiology and Molecular Genetics, Institute for Medical Research Israel-Canada, The Hebrew University-Hadassah Medical School, Jerusalem, Israel
- * E-mail:
| | - Peter Schuck
- Laboratory of Cellular Imaging and Macromolecular Biophysics, National Institute of Biomedical Imaging and Bioengineering, National Institutes of Health, Bethesda, Maryland, United States of America
| | - Terry M. Phillips
- Laboratory of Cellular Imaging and Macromolecular Biophysics, National Institute of Biomedical Imaging and Bioengineering, National Institutes of Health, Bethesda, Maryland, United States of America
| | - S. Brian Andrews
- Laboratory of Neurobiology, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, Maryland, United States of America
| | - Richard D. Leapman
- Laboratory of Cellular Imaging and Macromolecular Biophysics, National Institute of Biomedical Imaging and Bioengineering, National Institutes of Health, Bethesda, Maryland, United States of America
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30
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Shi J, Pagliaccia D, Morgan R, Qiao Y, Pan S, Vidalakis G, Ma W. Novel diagnosis for citrus stubborn disease by detection of a spiroplasma citri-secreted protein. PHYTOPATHOLOGY 2014; 104:188-195. [PMID: 23931112 DOI: 10.1094/phyto-06-13-0176-r] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
Citrus stubborn disease (CSD), first identified in California, is a widespread bacterial disease found in most arid citrus-producing regions in the United States and the Mediterranean Region. The disease is caused by Spiroplasma citri, an insect-transmitted and phloem-colonizing bacterium. CSD causes significant tree damage resulting in loss of fruit production and quality. Detection of CSD is challenging due to low and fluctuating titer and sporadic distribution of the pathogen in infected trees. In this study, we report the development of a novel diagnostic method for CSD using an S. citri-secreted protein as the detection marker. Microbial pathogens secrete a variety of proteins during infection that can potentially disperse systemically in infected plants with the vascular flow. Therefore, their distribution may not be restricted to the pathogen infection sites and could be used as a biological marker for infection. Using mass spectrometry analysis, we identified a unique secreted protein from S. citri that is highly expressed in the presence of citrus phloem extract. ScCCPP1, an antibody generated against this protein, was able to distinguish S. citri-infected citrus and periwinkle from healthy plants. In addition, the antiserum could be used to detect CSD using a simple direct tissue print assay without the need for sample processing or specialized lab equipment and may be suitable for field surveys. This study provides proof of a novel concept of using pathogen-secreted protein as a marker for diagnosis of a citrus bacterial disease and can probably be applied to other plant diseases.
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31
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Khanchezar A, Béven L, Izadpanah K, Salehi M, Saillard C. Spiralin diversity within Iranian strains of Spiroplasma citri. Curr Microbiol 2013; 68:96-104. [PMID: 23995776 DOI: 10.1007/s00284-013-0437-z] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2013] [Accepted: 07/15/2013] [Indexed: 10/26/2022]
Abstract
The first-cultured and most-studied spiroplasma is Spiroplasma citri, the causal agent of citrus stubborn disease, one of the three plant-pathogenic, sieve-tube-restricted, and leafhopper vector-transmitted mollicutes. In Iranian Fars province, S. citri cultures were obtained from stubborn affected citrus trees, sesame and safflower plants, and from the leafhopper vector Circulifer haematoceps. Spiralin gene sequences from different S. citri isolates were amplified by PCR, cloned, and sequenced. Phylogenetic trees based on spiralin gene sequence showed diversity and indicated the presence of three clusters among the S. citri strains. Comparison of the amino acid sequences of eleven spiralins from Iranian strains and those from the reference S. citri strain GII-3 (241 aa), Palmyre strain (242 aa), Spiroplasma kunkelii (240 aa), and Spiroplasma phoeniceum (237 aa) confirmed the conservation of general features of the protein. However, the spiralin of an S. citri isolate named Shiraz I comprised 346 amino acids and showed a large duplication of the region comprised between two short repeats previously identified in S. citri spiralins. We report in this paper the spiralin diversity in Spiroplasma strains from southern Iran and for the first time a partial internal duplication of the spiralin gene.
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Affiliation(s)
- Amin Khanchezar
- Plant Virology Research Centre (PVRC), College of Agriculture, Shiraz University, Shiraz, Iran
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32
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Lo WS, Chen LL, Chung WC, Gasparich GE, Kuo CH. Comparative genome analysis of Spiroplasma melliferum IPMB4A, a honeybee-associated bacterium. BMC Genomics 2013; 14:22. [PMID: 23324436 PMCID: PMC3563533 DOI: 10.1186/1471-2164-14-22] [Citation(s) in RCA: 75] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2012] [Accepted: 12/20/2012] [Indexed: 11/17/2022] Open
Abstract
Background The genus Spiroplasma contains a group of helical, motile, and wall-less bacteria in the class Mollicutes. Similar to other members of this class, such as the animal-pathogenic Mycoplasma and the plant-pathogenic ‘Candidatus Phytoplasma’, all characterized Spiroplasma species were found to be associated with eukaryotic hosts. While most of the Spiroplasma species appeared to be harmless commensals of insects, a small number of species have evolved pathogenicity toward various arthropods and plants. In this study, we isolated a novel strain of honeybee-associated S. melliferum and investigated its genetic composition and evolutionary history by whole-genome shotgun sequencing and comparative analysis with other Mollicutes genomes. Results The whole-genome shotgun sequencing of S. melliferum IPMB4A produced a draft assembly that was ~1.1 Mb in size and covered ~80% of the chromosome. Similar to other Spiroplasma genomes that have been studied to date, we found that this genome contains abundant repetitive sequences that originated from plectrovirus insertions. These phage fragments represented a major obstacle in obtaining a complete genome sequence of Spiroplasma with the current sequencing technology. Comparative analysis of S. melliferum IPMB4A with other Spiroplasma genomes revealed that these phages may have facilitated extensive genome rearrangements in these bacteria and contributed to horizontal gene transfers that led to species-specific adaptation to different eukaryotic hosts. In addition, comparison of gene content with other Mollicutes suggested that the common ancestor of the SEM (Spiroplasma, Entomoplasma, and Mycoplasma) clade may have had a relatively large genome and flexible metabolic capacity; the extremely reduced genomes of present day Mycoplasma and ‘Candidatus Phytoplasma’ species are likely to be the result of independent gene losses in these lineages. Conclusions The findings in this study highlighted the significance of phage insertions and horizontal gene transfer in the evolution of bacterial genomes and acquisition of pathogenicity. Furthermore, the inclusion of Spiroplasma in comparative analysis has improved our understanding of genome evolution in Mollicutes. Future improvements in the taxon sampling of available genome sequences in this group are required to provide further insights into the evolution of these important pathogens of humans, animals, and plants.
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Affiliation(s)
- Wen-Sui Lo
- Institute of Plant and Microbial Biology, Academia Sinica, Taipei, Taiwan
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The repetitive domain of ScARP3d triggers entry of Spiroplasma citri into cultured cells of the vector Circulifer haematoceps. PLoS One 2012; 7:e48606. [PMID: 23119070 PMCID: PMC3485318 DOI: 10.1371/journal.pone.0048606] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2012] [Accepted: 09/27/2012] [Indexed: 11/19/2022] Open
Abstract
Spiroplasma citri is a plant pathogenic mollicute transmitted by the leafhopper vector Circulifer haematoceps. Successful transmission requires the spiroplasmas to cross the intestinal epithelium and salivary gland barriers through endocytosis mediated by receptor-ligand interactions. To characterize these interactions we studied the adhesion and invasion capabilities of a S. citri mutant using the Ciha-1 leafhopper cell line. S. citri GII3 wild-type contains 7 plasmids, 5 of which (pSci1 to 5) encode 8 related adhesins (ScARPs). As compared to the wild-type strain GII3, the S. citri mutant G/6 lacking pSci1 to 5 was affected in its ability to adhere and enter into the Ciha-1 cells. Proteolysis analyses, Triton X-114 partitioning and agglutination assays showed that the N-terminal part of ScARP3d, consisting of repeated sequences, was exposed to the spiroplasma surface whereas the C-terminal part was anchored into the membrane. Latex beads cytadherence assays showed the ScARP3d repeat domain (Rep3d) to be involved, and internalization of the Rep3d-coated beads to be actin-dependent. These data suggested that ScARP3d, via its Rep3d domain, was implicated in adhesion of S. citri GII3 to insect cells. Inhibition tests using anti-Rep3d antibodies and competitive assays with recombinant Rep3d both resulted in a decrease of insect cells invasion by the spiroplasmas. Unexpectedly, treatment of Ciha-1 cells with the actin polymerisation inhibitor cytochalasin D increased adhesion and consequently entry of S. citri GII3. For the ScARPs-less mutant G/6, only adhesion was enhanced though to a lesser extent following cytochalasin D treatment. All together these results strongly suggest a role of ScARPs, and particularly ScARP3d, in adhesion and invasion of the leafhopper cells by S. citri.
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Zhaxybayeva O, Swithers KS, Foght J, Green AG, Bruce D, Detter C, Han S, Teshima H, Han J, Woyke T, Pitluck S, Nolan M, Ivanova N, Pati A, Land ML, Dlutek M, Doolittle WF, Noll KM, Nesbø CL. Genome sequence of the mesophilic Thermotogales bacterium Mesotoga prima MesG1.Ag.4.2 reveals the largest Thermotogales genome to date. Genome Biol Evol 2012; 4:700-8. [PMID: 22798451 PMCID: PMC3516359 DOI: 10.1093/gbe/evs059] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Here we describe the genome of Mesotoga prima MesG1.Ag4.2, the first genome of a mesophilic Thermotogales bacterium. Mesotoga prima was isolated from a polychlorinated biphenyl (PCB)-dechlorinating enrichment culture from Baltimore Harbor sediments. Its 2.97 Mb genome is considerably larger than any previously sequenced Thermotogales genomes, which range between 1.86 and 2.30 Mb. This larger size is due to both higher numbers of protein-coding genes and larger intergenic regions. In particular, the M. prima genome contains more genes for proteins involved in regulatory functions, for instance those involved in regulation of transcription. Together with its closest relative, Kosmotoga olearia, it also encodes different types of proteins involved in environmental and cell-cell interactions as compared with other Thermotogales bacteria. Amino acid composition analysis of M. prima proteins implies that this lineage has inhabited low-temperature environments for a long time. A large fraction of the M. prima genome has been acquired by lateral gene transfer (LGT): a DarkHorse analysis suggests that 766 (32%) of predicted protein-coding genes have been involved in LGT after Mesotoga diverged from the other Thermotogales lineages. A notable example of a lineage-specific LGT event is a reductive dehalogenase gene-a key enzyme in dehalorespiration, indicating M. prima may have a more active role in PCB dechlorination than was previously assumed.
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Affiliation(s)
- Olga Zhaxybayeva
- Department of Biology, West Virginia University
- Department of Biological Sciences, Dartmouth College
| | | | - Julia Foght
- Department of Biological Sciences, University of Alberta, Edmonton, Canada
| | - Anna G. Green
- Department of Molecular and Cell Biology, University of Connecticut
| | - David Bruce
- Los Alamos National Laboratory, Bioscience Division, Los Alamos, New Mexico
| | - Chris Detter
- Los Alamos National Laboratory, Bioscience Division, Los Alamos, New Mexico
| | - Shunsheng Han
- Los Alamos National Laboratory, Bioscience Division, Los Alamos, New Mexico
| | - Hazuki Teshima
- Los Alamos National Laboratory, Bioscience Division, Los Alamos, New Mexico
| | - James Han
- DOE Joint Genome Institute, Walnut Creek, California
| | - Tanja Woyke
- DOE Joint Genome Institute, Walnut Creek, California
| | - Sam Pitluck
- DOE Joint Genome Institute, Walnut Creek, California
| | - Matt Nolan
- DOE Joint Genome Institute, Walnut Creek, California
| | | | - Amrita Pati
- DOE Joint Genome Institute, Walnut Creek, California
| | | | - Marlena Dlutek
- Department of Biochemistry and Molecular Biology, Dalhousie University, Halifax, Canada
| | - W. Ford Doolittle
- Department of Biochemistry and Molecular Biology, Dalhousie University, Halifax, Canada
| | - Kenneth M. Noll
- Department of Molecular and Cell Biology, University of Connecticut
| | - Camilla L. Nesbø
- Department of Biological Sciences, University of Alberta, Edmonton, Canada
- Centre for Ecological and Evolutionary Synthesis (CEES), Department of Biology, University of Oslo, Oslo, Norway
- *Corresponding author: E-mail:
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Alexeev D, Kostrjukova E, Aliper A, Popenko A, Bazaleev N, Tyakht A, Selezneva O, Akopian T, Prichodko E, Kondratov I, Chukin M, Demina I, Galyamina M, Kamashev D, Vanyushkina A, Ladygina V, Levitskii S, Lazarev V, Govorun V. Application of Spiroplasma melliferum Proteogenomic Profiling for the Discovery of Virulence Factors and Pathogenicity Mechanisms in Host-associated Spiroplasmas. J Proteome Res 2011; 11:224-36. [DOI: 10.1021/pr2008626] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Dmitry Alexeev
- Russian Institute of Physico-Chemical Medicine, Malaya Pirogovskaya 1a,
Moscow, Russian Federation
- Moscow Institute of Physics and Technology - Bioinformatics Dolgoprudny,
Pervomayskaya 21 , Moscow 117303, Russian Federation
| | - Elena Kostrjukova
- Russian Institute of Physico-Chemical Medicine, Malaya Pirogovskaya 1a,
Moscow, Russian Federation
| | - Alexander Aliper
- Russian Institute of Physico-Chemical Medicine, Malaya Pirogovskaya 1a,
Moscow, Russian Federation
| | - Anna Popenko
- Russian Institute of Physico-Chemical Medicine, Malaya Pirogovskaya 1a,
Moscow, Russian Federation
| | - Nikolay Bazaleev
- Russian Institute of Physico-Chemical Medicine, Malaya Pirogovskaya 1a,
Moscow, Russian Federation
| | - Alexander Tyakht
- Russian Institute of Physico-Chemical Medicine, Malaya Pirogovskaya 1a,
Moscow, Russian Federation
| | - Oksana Selezneva
- Russian Institute of Physico-Chemical Medicine, Malaya Pirogovskaya 1a,
Moscow, Russian Federation
- Russian Research Centre Kurchatov Institute, pl. Akademika Kurchatova
1, Moscow 123182, Russian Federation
| | - Tatyana Akopian
- Russian Institute of Physico-Chemical Medicine, Malaya Pirogovskaya 1a,
Moscow, Russian Federation
| | - Elena Prichodko
- Russian Institute of Physico-Chemical Medicine, Malaya Pirogovskaya 1a,
Moscow, Russian Federation
| | - Ilya Kondratov
- Russian Institute of Physico-Chemical Medicine, Malaya Pirogovskaya 1a,
Moscow, Russian Federation
| | - Mikhail Chukin
- Russian Institute of Physico-Chemical Medicine, Malaya Pirogovskaya 1a,
Moscow, Russian Federation
| | - Irina Demina
- Russian Institute of Physico-Chemical Medicine, Malaya Pirogovskaya 1a,
Moscow, Russian Federation
| | - Maria Galyamina
- Russian Institute of Physico-Chemical Medicine, Malaya Pirogovskaya 1a,
Moscow, Russian Federation
| | - Dmitri Kamashev
- Russian Institute of Physico-Chemical Medicine, Malaya Pirogovskaya 1a,
Moscow, Russian Federation
- Russian Research Centre Kurchatov Institute, pl. Akademika Kurchatova
1, Moscow 123182, Russian Federation
| | - Anna Vanyushkina
- Russian Institute of Physico-Chemical Medicine, Malaya Pirogovskaya 1a,
Moscow, Russian Federation
- Russian Research Centre Kurchatov Institute, pl. Akademika Kurchatova
1, Moscow 123182, Russian Federation
| | - Valentina Ladygina
- Russian Institute of Physico-Chemical Medicine, Malaya Pirogovskaya 1a,
Moscow, Russian Federation
| | - Sergei Levitskii
- Russian Institute of Physico-Chemical Medicine, Malaya Pirogovskaya 1a,
Moscow, Russian Federation
- Russian Research Centre Kurchatov Institute, pl. Akademika Kurchatova
1, Moscow 123182, Russian Federation
| | - Vasily Lazarev
- Russian Institute of Physico-Chemical Medicine, Malaya Pirogovskaya 1a,
Moscow, Russian Federation
- Russian Research Centre Kurchatov Institute, pl. Akademika Kurchatova
1, Moscow 123182, Russian Federation
| | - Vadim Govorun
- Russian Institute of Physico-Chemical Medicine, Malaya Pirogovskaya 1a,
Moscow, Russian Federation
- Russian Research Centre Kurchatov Institute, pl. Akademika Kurchatova
1, Moscow 123182, Russian Federation
- M.M. Shemyakin–Yu.A. Ovchinnikov Institute of Bioorganic Chemistry, Ul. Miklukho-Maklaya,
16/10 , Moscow 117997, Russian Federation
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Mutaqin K, Comer JL, Wayadande AC, Melcher U, Fletcher J. Selection and characterization ofSpiroplasma citrimutants by random transposome mutagenesis. Can J Microbiol 2011; 57:525-32. [DOI: 10.1139/w11-026] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Phytopathogenic spiroplasmas can multiply in vascular plants and insects. A deeper understanding of this dual-host life could be furthered through the identification by random mutagenesis of spiroplasma genes required. The ability of the EZ::TN™ <DHFR-1> Tnp transposome™ system to create random insertional mutations in the genome of Spiroplasma citri was evaluated. The efficiency of electroporation-mediated transformation of S. citri BR3-3X averaged 28.8 CFUs/ng transposome for 109spiroplasma cells. Many transformants appearing on the selection plates were growth impaired when transferred to broth. Altering broth composition in various ways did not improve their growth. However, placing colonies into a small broth volume resulted in robust growth and successful subsequent passages of a subset of transformants. PCR using primers for the dihydrofolate reductase gene confirmed the transposon’s presence in the genomes of selected transformants. Southern blot hybridization and nucleotide sequencing suggested that insertion was random within the chromosome and usually at single sites. The insertions were stable. Growth rates of all transformants were lower than that of the wild-type S. citri, but none lost the ability to adhere to a Circulifer tenellus (CT-1) cell line. The EZ::TN™ <DHFR-1> Tnp transposome™ system represents an additional tool for genetic manipulation of the fastidious spiroplasmas.
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Affiliation(s)
- Kikin Mutaqin
- Department of Entomology and Plant Pathology, and Department of Biochemistry and Molecular Biology, Oklahoma State University, Stillwater, OK 74078, USA
| | - Jana L. Comer
- Department of Entomology and Plant Pathology, and Department of Biochemistry and Molecular Biology, Oklahoma State University, Stillwater, OK 74078, USA
| | - Astri C. Wayadande
- Department of Entomology and Plant Pathology, and Department of Biochemistry and Molecular Biology, Oklahoma State University, Stillwater, OK 74078, USA
| | - Ulrich Melcher
- Department of Entomology and Plant Pathology, and Department of Biochemistry and Molecular Biology, Oklahoma State University, Stillwater, OK 74078, USA
| | - Jacqueline Fletcher
- Department of Entomology and Plant Pathology, and Department of Biochemistry and Molecular Biology, Oklahoma State University, Stillwater, OK 74078, USA
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Breton M, Duret S, Béven L, Dubrana MP, Renaudin J. I-SceI-mediated plasmid deletion and intra-molecular recombination in Spiroplasma citri. J Microbiol Methods 2010; 84:216-22. [PMID: 21129414 DOI: 10.1016/j.mimet.2010.11.020] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2010] [Revised: 11/16/2010] [Accepted: 11/23/2010] [Indexed: 12/27/2022]
Abstract
S. citri wild-type strain GII3 carries six plasmids (pSci1 to -6) that are thought to encode determinants involved in the transmission of the spiroplasma by its leafhopper vector. In this study we report the use of meganuclease I-SceI for plasmid deletion in S. citri. Plasmids pSci1NT-I and pSci6PT-I, pSci1 and pSci6 derivatives that contain the tetM selection marker and a unique I-SceI recognition site were first introduced into S. citri strains 44 (having no plasmid) and GII3 (carrying pSci1-6), respectively. Due to incompatibility of homologous replication regions, propagation of the S. citri GII3 transformant in selective medium resulted in the replacement of the natural pSci6 by pSci6PT-I. The spiroplasmal transformants were further transformed by an oriC plasmid carrying the I-SceI gene under the control of the spiralin gene promoter. In the S. citri 44 transformant, expression of I-SceI resulted in rapid loss of pSciNT-I showing that expression of I-SceI can be used as a counter-selection tool in spiroplasmas. In the case of the S. citri GII3 transformant carrying pSci6PT-I, expression of I-SceI resulted in the deletion of plasmid fragments comprising the I-SceI site and the tetM marker. Delineating the I-SceI generated deletions proved they had occurred though recombination between homologous sequences. To our knowledge this is the first report of I-SceI mediated intra-molecular recombination in mollicutes.
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Affiliation(s)
- Marc Breton
- INRA, Génomique Diversité et Pouvoir Pathogéne, Villenave d'Ornon, France
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Carle P, Saillard C, Carrère N, Carrère S, Duret S, Eveillard S, Gaurivaud P, Gourgues G, Gouzy J, Salar P, Verdin E, Breton M, Blanchard A, Laigret F, Bové JM, Renaudin J, Foissac X. Partial chromosome sequence of Spiroplasma citri reveals extensive viral invasion and important gene decay. Appl Environ Microbiol 2010; 76:3420-6. [PMID: 20363791 PMCID: PMC2876439 DOI: 10.1128/aem.02954-09] [Citation(s) in RCA: 54] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2009] [Accepted: 03/25/2010] [Indexed: 11/20/2022] Open
Abstract
The assembly of 20,000 sequencing reads obtained from shotgun and chromosome-specific libraries of the Spiroplasma citri genome yielded 77 chromosomal contigs totaling 1,674 kbp (92%) of the 1,820-kbp chromosome. The largest chromosomal contigs were positioned on the physical and genetic maps constructed from pulsed-field gel electrophoresis and Southern blot hybridizations. Thirty-eight contigs were annotated, resulting in 1,908 predicted coding sequences (CDS) representing an overall coding density of only 74%. Cellular processes, cell metabolism, and structural-element CDS account for 29% of the coding capacity, CDS of external origin such as viruses and mobile elements account for 24% of the coding capacity, and CDS of unknown function account for 47% of the coding capacity. Among these, 21% of the CDS group into 63 paralog families. The organization of these paralogs into conserved blocks suggests that they represent potential mobile units. Phage-related sequences were particularly abundant and include plectrovirus SpV1 and SVGII3 and lambda-like SpV2 sequences. Sixty-nine copies of transposases belonging to four insertion sequence (IS) families (IS30, IS481, IS3, and ISNCY) were detected. Similarity analyses showed that 21% of chromosomal CDS were truncated compared to their bacterial orthologs. Transmembrane domains, including signal peptides, were predicted for 599 CDS, of which 58 were putative lipoproteins. S. citri has a Sec-dependent protein export pathway. Eighty-four CDS were assigned to transport, such as phosphoenolpyruvate phosphotransferase systems (PTS), the ATP binding cassette (ABC), and other transporters. Besides glycolytic and ATP synthesis pathways, it is noteworthy that S. citri possesses a nearly complete pathway for the biosynthesis of a terpenoid.
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Affiliation(s)
- Patricia Carle
- INRA, UMR1090 Génomique Diversité Pouvoir Pathogène, 71 Avenue Edouard Bourlaux, BP81, F-33883 Villenave d'Ornon Cedex, France, Université Victor Segalen Bordeaux 2, UMR1090, F-33883 Villenave d'Ornon, France, INRA, CNRS, Laboratoire Interactions Plantes Micro-Organismes UMR441/2594, F-31320 Castanet Tolosan, France, INRA, UR419 Espèces Fruitières, 71 Avenue Edouard Bourlaux, BP81, F-33883 Villenave d'Ornon Cedex, France
| | - Colette Saillard
- INRA, UMR1090 Génomique Diversité Pouvoir Pathogène, 71 Avenue Edouard Bourlaux, BP81, F-33883 Villenave d'Ornon Cedex, France, Université Victor Segalen Bordeaux 2, UMR1090, F-33883 Villenave d'Ornon, France, INRA, CNRS, Laboratoire Interactions Plantes Micro-Organismes UMR441/2594, F-31320 Castanet Tolosan, France, INRA, UR419 Espèces Fruitières, 71 Avenue Edouard Bourlaux, BP81, F-33883 Villenave d'Ornon Cedex, France
| | - Nathalie Carrère
- INRA, UMR1090 Génomique Diversité Pouvoir Pathogène, 71 Avenue Edouard Bourlaux, BP81, F-33883 Villenave d'Ornon Cedex, France, Université Victor Segalen Bordeaux 2, UMR1090, F-33883 Villenave d'Ornon, France, INRA, CNRS, Laboratoire Interactions Plantes Micro-Organismes UMR441/2594, F-31320 Castanet Tolosan, France, INRA, UR419 Espèces Fruitières, 71 Avenue Edouard Bourlaux, BP81, F-33883 Villenave d'Ornon Cedex, France
| | - Sébastien Carrère
- INRA, UMR1090 Génomique Diversité Pouvoir Pathogène, 71 Avenue Edouard Bourlaux, BP81, F-33883 Villenave d'Ornon Cedex, France, Université Victor Segalen Bordeaux 2, UMR1090, F-33883 Villenave d'Ornon, France, INRA, CNRS, Laboratoire Interactions Plantes Micro-Organismes UMR441/2594, F-31320 Castanet Tolosan, France, INRA, UR419 Espèces Fruitières, 71 Avenue Edouard Bourlaux, BP81, F-33883 Villenave d'Ornon Cedex, France
| | - Sybille Duret
- INRA, UMR1090 Génomique Diversité Pouvoir Pathogène, 71 Avenue Edouard Bourlaux, BP81, F-33883 Villenave d'Ornon Cedex, France, Université Victor Segalen Bordeaux 2, UMR1090, F-33883 Villenave d'Ornon, France, INRA, CNRS, Laboratoire Interactions Plantes Micro-Organismes UMR441/2594, F-31320 Castanet Tolosan, France, INRA, UR419 Espèces Fruitières, 71 Avenue Edouard Bourlaux, BP81, F-33883 Villenave d'Ornon Cedex, France
| | - Sandrine Eveillard
- INRA, UMR1090 Génomique Diversité Pouvoir Pathogène, 71 Avenue Edouard Bourlaux, BP81, F-33883 Villenave d'Ornon Cedex, France, Université Victor Segalen Bordeaux 2, UMR1090, F-33883 Villenave d'Ornon, France, INRA, CNRS, Laboratoire Interactions Plantes Micro-Organismes UMR441/2594, F-31320 Castanet Tolosan, France, INRA, UR419 Espèces Fruitières, 71 Avenue Edouard Bourlaux, BP81, F-33883 Villenave d'Ornon Cedex, France
| | - Patrice Gaurivaud
- INRA, UMR1090 Génomique Diversité Pouvoir Pathogène, 71 Avenue Edouard Bourlaux, BP81, F-33883 Villenave d'Ornon Cedex, France, Université Victor Segalen Bordeaux 2, UMR1090, F-33883 Villenave d'Ornon, France, INRA, CNRS, Laboratoire Interactions Plantes Micro-Organismes UMR441/2594, F-31320 Castanet Tolosan, France, INRA, UR419 Espèces Fruitières, 71 Avenue Edouard Bourlaux, BP81, F-33883 Villenave d'Ornon Cedex, France
| | - Géraldine Gourgues
- INRA, UMR1090 Génomique Diversité Pouvoir Pathogène, 71 Avenue Edouard Bourlaux, BP81, F-33883 Villenave d'Ornon Cedex, France, Université Victor Segalen Bordeaux 2, UMR1090, F-33883 Villenave d'Ornon, France, INRA, CNRS, Laboratoire Interactions Plantes Micro-Organismes UMR441/2594, F-31320 Castanet Tolosan, France, INRA, UR419 Espèces Fruitières, 71 Avenue Edouard Bourlaux, BP81, F-33883 Villenave d'Ornon Cedex, France
| | - Jérome Gouzy
- INRA, UMR1090 Génomique Diversité Pouvoir Pathogène, 71 Avenue Edouard Bourlaux, BP81, F-33883 Villenave d'Ornon Cedex, France, Université Victor Segalen Bordeaux 2, UMR1090, F-33883 Villenave d'Ornon, France, INRA, CNRS, Laboratoire Interactions Plantes Micro-Organismes UMR441/2594, F-31320 Castanet Tolosan, France, INRA, UR419 Espèces Fruitières, 71 Avenue Edouard Bourlaux, BP81, F-33883 Villenave d'Ornon Cedex, France
| | - Pascal Salar
- INRA, UMR1090 Génomique Diversité Pouvoir Pathogène, 71 Avenue Edouard Bourlaux, BP81, F-33883 Villenave d'Ornon Cedex, France, Université Victor Segalen Bordeaux 2, UMR1090, F-33883 Villenave d'Ornon, France, INRA, CNRS, Laboratoire Interactions Plantes Micro-Organismes UMR441/2594, F-31320 Castanet Tolosan, France, INRA, UR419 Espèces Fruitières, 71 Avenue Edouard Bourlaux, BP81, F-33883 Villenave d'Ornon Cedex, France
| | - Eric Verdin
- INRA, UMR1090 Génomique Diversité Pouvoir Pathogène, 71 Avenue Edouard Bourlaux, BP81, F-33883 Villenave d'Ornon Cedex, France, Université Victor Segalen Bordeaux 2, UMR1090, F-33883 Villenave d'Ornon, France, INRA, CNRS, Laboratoire Interactions Plantes Micro-Organismes UMR441/2594, F-31320 Castanet Tolosan, France, INRA, UR419 Espèces Fruitières, 71 Avenue Edouard Bourlaux, BP81, F-33883 Villenave d'Ornon Cedex, France
| | - Marc Breton
- INRA, UMR1090 Génomique Diversité Pouvoir Pathogène, 71 Avenue Edouard Bourlaux, BP81, F-33883 Villenave d'Ornon Cedex, France, Université Victor Segalen Bordeaux 2, UMR1090, F-33883 Villenave d'Ornon, France, INRA, CNRS, Laboratoire Interactions Plantes Micro-Organismes UMR441/2594, F-31320 Castanet Tolosan, France, INRA, UR419 Espèces Fruitières, 71 Avenue Edouard Bourlaux, BP81, F-33883 Villenave d'Ornon Cedex, France
| | - Alain Blanchard
- INRA, UMR1090 Génomique Diversité Pouvoir Pathogène, 71 Avenue Edouard Bourlaux, BP81, F-33883 Villenave d'Ornon Cedex, France, Université Victor Segalen Bordeaux 2, UMR1090, F-33883 Villenave d'Ornon, France, INRA, CNRS, Laboratoire Interactions Plantes Micro-Organismes UMR441/2594, F-31320 Castanet Tolosan, France, INRA, UR419 Espèces Fruitières, 71 Avenue Edouard Bourlaux, BP81, F-33883 Villenave d'Ornon Cedex, France
| | - Frédéric Laigret
- INRA, UMR1090 Génomique Diversité Pouvoir Pathogène, 71 Avenue Edouard Bourlaux, BP81, F-33883 Villenave d'Ornon Cedex, France, Université Victor Segalen Bordeaux 2, UMR1090, F-33883 Villenave d'Ornon, France, INRA, CNRS, Laboratoire Interactions Plantes Micro-Organismes UMR441/2594, F-31320 Castanet Tolosan, France, INRA, UR419 Espèces Fruitières, 71 Avenue Edouard Bourlaux, BP81, F-33883 Villenave d'Ornon Cedex, France
| | - Joseph-Marie Bové
- INRA, UMR1090 Génomique Diversité Pouvoir Pathogène, 71 Avenue Edouard Bourlaux, BP81, F-33883 Villenave d'Ornon Cedex, France, Université Victor Segalen Bordeaux 2, UMR1090, F-33883 Villenave d'Ornon, France, INRA, CNRS, Laboratoire Interactions Plantes Micro-Organismes UMR441/2594, F-31320 Castanet Tolosan, France, INRA, UR419 Espèces Fruitières, 71 Avenue Edouard Bourlaux, BP81, F-33883 Villenave d'Ornon Cedex, France
| | - Joel Renaudin
- INRA, UMR1090 Génomique Diversité Pouvoir Pathogène, 71 Avenue Edouard Bourlaux, BP81, F-33883 Villenave d'Ornon Cedex, France, Université Victor Segalen Bordeaux 2, UMR1090, F-33883 Villenave d'Ornon, France, INRA, CNRS, Laboratoire Interactions Plantes Micro-Organismes UMR441/2594, F-31320 Castanet Tolosan, France, INRA, UR419 Espèces Fruitières, 71 Avenue Edouard Bourlaux, BP81, F-33883 Villenave d'Ornon Cedex, France
| | - Xavier Foissac
- INRA, UMR1090 Génomique Diversité Pouvoir Pathogène, 71 Avenue Edouard Bourlaux, BP81, F-33883 Villenave d'Ornon Cedex, France, Université Victor Segalen Bordeaux 2, UMR1090, F-33883 Villenave d'Ornon, France, INRA, CNRS, Laboratoire Interactions Plantes Micro-Organismes UMR441/2594, F-31320 Castanet Tolosan, France, INRA, UR419 Espèces Fruitières, 71 Avenue Edouard Bourlaux, BP81, F-33883 Villenave d'Ornon Cedex, France
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Sequences essential for transmission of Spiroplasma citri by its leafhopper vector, Circulifer haematoceps, revealed by plasmid curing and replacement based on incompatibility. Appl Environ Microbiol 2010; 76:3198-205. [PMID: 20305023 DOI: 10.1128/aem.00181-10] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Spiroplasma citri GII3 contains highly related low-copy-number plasmids pSci1 to -6. Despite the strong similarities between their replication regions, these plasmids coexist in the spiroplasma cells, indicating that they are mutually compatible. The pSci1 to -6 plasmids encode the membrane proteins known as S. citri adhesion-related proteins (ScARPs) (pSci1 to -5) and the hydrophilic protein P32 (pSci6), which had been tentatively associated with insect transmission, as they were not detected in non-insect-transmissible strains. With the aim of further investigating the role of plasmid-encoded determinants in insect transmission, we have constructed S. citri mutant strains that differ in their plasmid contents by developing a plasmid curing/replacement strategy based on the incompatibility of plasmids having identical replication regions. Experimental transmission of these S. citri plasmid mutants through injection into the leafhopper vector Circulifer haematoceps revealed that pSci6, more precisely, the pSci6_06 coding sequence, encoding a protein of unknown function, was essential for transmission. In contrast, ScARPs and P32 were dispensable for both acquisition and transmission of the spiroplasmas by the leafhopper vector, even though S. citri mutants lacking pSci1 to -5 (encoding ScARPs) were acquired and transmitted at lower efficiencies than the wild-type strain GII3.
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Entry of Spiroplasma citri into Circulifer haematoceps cells involves interaction between spiroplasma phosphoglycerate kinase and leafhopper actin. Appl Environ Microbiol 2010; 76:1879-86. [PMID: 20118377 DOI: 10.1128/aem.02384-09] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Transmission of the phytopathogenic mollicutes, spiroplasmas, and phytoplasmas by their insect vectors mainly depends on their ability to pass through gut cells, to multiply in various tissues, and to traverse the salivary gland cells. The passage of these different barriers suggests molecular interactions between the plant mollicute and the insect vector that regulate transmission. In the present study, we focused on the interaction between Spiroplasma citri and its leafhopper vector, Circulifer haematoceps. An in vitro protein overlay assay identified five significant binding activities between S. citri proteins and insect host proteins from salivary glands. One insect protein involved in one binding activity was identified by liquid chromatography-tandem mass spectrometry (LC-MS/MS) as actin. Confocal microscopy observations of infected salivary glands revealed that spiroplasmas colocated with the host actin filaments. An S. citri actin-binding protein of 44 kDa was isolated by affinity chromatography and identified by LC-MS/MS as phosphoglycerate kinase (PGK). To investigate the role of the PGK-actin interaction, we performed competitive binding and internalization assays on leafhopper cultured cell lines (Ciha-1) in which His(6)-tagged PGK from S. citri or purified PGK from Saccharomyces cerevisiae was added prior to the addition of S. citri inoculum. The results suggested that exogenous PGK has no effect on spiroplasmal attachment to leafhopper cell surfaces but inhibits S. citri internalization, demonstrating that the process leading to internalization of S. citri in eukaryotic cells requires the presence of PGK. PGK, regardless of origin, reduced the entry of spiroplasmas into Ciha-1 cells in a dose-dependent manner.
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Duret S, Batailler B, Danet JL, Béven L, Renaudin J, Arricau-Bouvery N. Infection of the Circulifer haematoceps cell line Ciha-1 by Spiroplasma citri: the non-insect-transmissible strain 44 is impaired in invasion. MICROBIOLOGY-SGM 2009; 156:1097-1107. [PMID: 20019079 DOI: 10.1099/mic.0.035063-0] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Successful transmission of Spiroplasma citri by its leafhopper vector requires a specific interaction between the spiroplasma surface and the insect cells. With the aim of studying these interactions at the cellular and molecular levels, a cell line, named Ciha-1, was established using embryonic tissues from the eggs of the S. citri natural vector Circulifer haematoceps. This is the first report, to our knowledge, of a cell line for this leafhopper species and of its successful infection by the insect-transmissible strain S. citri GII3. Adherence of the spiroplasmas to the cultured Ciha-1 cells was studied by c.f.u. counts and by electron microscopy. Entry of the spiroplasmas into the insect cells was analysed quantitatively by gentamicin protection assays and qualitatively by double immunofluorescence microscopy. Spiroplasmas were detected within the cell cytoplasm as early as 1 h after inoculation and survived at least 2 days inside the cells. Comparing the insect-transmissible GII3 and non-insect-transmissible 44 strains revealed that adherence to and entry into Ciha-1 cells of S. citri 44 were significantly less efficient than those of S. citri GII3.
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Affiliation(s)
- Sybille Duret
- Université de Bordeaux 2, UMR 1090 Génomique Diversité et Pouvoir Pathogène, F-33883 Villenave d'Ornon, France.,INRA, Centre de Bordeaux-Aquitaine, UMR 1090 Génomique Diversité et Pouvoir Pathogène, F-33883 Villenave d'Ornon, France
| | - Brigitte Batailler
- Plateau Technique Imagerie/Cytologie, INRA, Centre de Bordeaux-Aquitaine, F-33883 Villenave d'Ornon, France.,Université de Bordeaux 2, UMR 1090 Génomique Diversité et Pouvoir Pathogène, F-33883 Villenave d'Ornon, France.,INRA, Centre de Bordeaux-Aquitaine, UMR 1090 Génomique Diversité et Pouvoir Pathogène, F-33883 Villenave d'Ornon, France
| | - Jean-Luc Danet
- Université de Bordeaux 2, UMR 1090 Génomique Diversité et Pouvoir Pathogène, F-33883 Villenave d'Ornon, France.,INRA, Centre de Bordeaux-Aquitaine, UMR 1090 Génomique Diversité et Pouvoir Pathogène, F-33883 Villenave d'Ornon, France
| | - Laure Béven
- Université de Bordeaux 2, UMR 1090 Génomique Diversité et Pouvoir Pathogène, F-33883 Villenave d'Ornon, France.,INRA, Centre de Bordeaux-Aquitaine, UMR 1090 Génomique Diversité et Pouvoir Pathogène, F-33883 Villenave d'Ornon, France
| | - Joël Renaudin
- Université de Bordeaux 2, UMR 1090 Génomique Diversité et Pouvoir Pathogène, F-33883 Villenave d'Ornon, France.,INRA, Centre de Bordeaux-Aquitaine, UMR 1090 Génomique Diversité et Pouvoir Pathogène, F-33883 Villenave d'Ornon, France
| | - Nathalie Arricau-Bouvery
- Université de Bordeaux 2, UMR 1090 Génomique Diversité et Pouvoir Pathogène, F-33883 Villenave d'Ornon, France.,INRA, Centre de Bordeaux-Aquitaine, UMR 1090 Génomique Diversité et Pouvoir Pathogène, F-33883 Villenave d'Ornon, France
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42
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Alvarez-Martinez CE, Christie PJ. Biological diversity of prokaryotic type IV secretion systems. Microbiol Mol Biol Rev 2009; 73:775-808. [PMID: 19946141 PMCID: PMC2786583 DOI: 10.1128/mmbr.00023-09] [Citation(s) in RCA: 524] [Impact Index Per Article: 34.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Type IV secretion systems (T4SS) translocate DNA and protein substrates across prokaryotic cell envelopes generally by a mechanism requiring direct contact with a target cell. Three types of T4SS have been described: (i) conjugation systems, operationally defined as machines that translocate DNA substrates intercellularly by a contact-dependent process; (ii) effector translocator systems, functioning to deliver proteins or other macromolecules to eukaryotic target cells; and (iii) DNA release/uptake systems, which translocate DNA to or from the extracellular milieu. Studies of a few paradigmatic systems, notably the conjugation systems of plasmids F, R388, RP4, and pKM101 and the Agrobacterium tumefaciens VirB/VirD4 system, have supplied important insights into the structure, function, and mechanism of action of type IV secretion machines. Information on these systems is updated, with emphasis on recent exciting structural advances. An underappreciated feature of T4SS, most notably of the conjugation subfamily, is that they are widely distributed among many species of gram-negative and -positive bacteria, wall-less bacteria, and the Archaea. Conjugation-mediated lateral gene transfer has shaped the genomes of most if not all prokaryotes over evolutionary time and also contributed in the short term to the dissemination of antibiotic resistance and other virulence traits among medically important pathogens. How have these machines adapted to function across envelopes of distantly related microorganisms? A survey of T4SS functioning in phylogenetically diverse species highlights the biological complexity of these translocation systems and identifies common mechanistic themes as well as novel adaptations for specialized purposes relating to the modulation of the donor-target cell interaction.
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Affiliation(s)
- Cristina E. Alvarez-Martinez
- Department of Microbiology and Molecular Genetics, University of Texas Medical School at Houston, 6431 Fannin, Houston, Texas 77030
| | - Peter J. Christie
- Department of Microbiology and Molecular Genetics, University of Texas Medical School at Houston, 6431 Fannin, Houston, Texas 77030
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43
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Cimerman A, Pacifico D, Salar P, Marzachì C, Foissac X. Striking diversity of vmp1, a variable gene encoding a putative membrane protein of the stolbur phytoplasma. Appl Environ Microbiol 2009; 75:2951-7. [PMID: 19270150 PMCID: PMC2681707 DOI: 10.1128/aem.02613-08] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2008] [Accepted: 02/25/2009] [Indexed: 11/20/2022] Open
Abstract
Studies of phytoplasma-insect vector interactions and epidemiological surveys of plant yellows associated with the stolbur phytoplasma (StolP) require the identification of relevant candidate genes and typing markers. A recent StolP genome survey identified a partial coding sequence, SR01H10, having no homologue in the "Candidatus Phytoplasma asteris" genome but sharing low similarity with a variable surface protein of animal mycoplasmas. The complete coding sequence and its genetic environment have been fully characterized by chromosome walking. The vmp1 gene encodes a protein of 557 amino acids predicted to possess a putative signal peptide and a potential C-terminal transmembrane domain. The mature 57.8-kDa VMP1 protein is likely to be anchored in the phytoplasma membrane with a large N-terminal hydrophilic part exposed to the phytoplasma cell surface. Southern blotting experiments detected multiple sequences homologous to vmp1 in the genomes of nine StolP isolates. vmp1 is variable in size, and eight different vmp1 RsaI restriction fragment length polymorphism types could be distinguished among 12 StolP isolates. Comparison of vmp1 sequences revealed that insertions in largest forms of the gene encode an additional copy of a repeated domain of 81 amino acids, while variations in 11-bp repeats led to gene disruption in two StolP isolates. vmp1 appeared to be much more variable than three housekeeping genes involved in protein translation, maturation, and secretion and may therefore be involved in phytoplasma-host interactions.
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Affiliation(s)
- Agnès Cimerman
- UMR 1090 Génomique Diversité Pouvoir Pathogène, INRA, 71 avenue Edouard Bourlaux BP 81, F-33883 Villenave d'Ornon, France
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44
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Breton M, Duret S, Arricau-Bouvery N, Béven L, Renaudin J. Characterizing the replication and stability regions of Spiroplasma citri plasmids identifies a novel replication protein and expands the genetic toolbox for plant-pathogenic spiroplasmas. MICROBIOLOGY-SGM 2008; 154:3232-3244. [PMID: 18832328 DOI: 10.1099/mic.0.2008/019562-0] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Spiroplasma citri strain GII3 contains seven plasmids, pSciA and pSci1-6, that share extensive regions of sequence homology and display a mosaic gene organization. Plasmid pSci2 comprises 12 coding sequences (CDS), three of which encode polypeptides homologous to proteins Soj/ParA, involved in chromosome partitioning, and TrsE and Mob/TraG, implicated in the type IV secretion pathway. One CDS encodes the adhesin-like protein ScARP3d whereas the other eight encode polypeptides with no homology to known proteins. The pSci2 CDS pE and soj have counterparts in all seven plasmids. Through successive deletions, various pSci2 derivatives were constructed and assessed for their ability to replicate by transformation of S. citri 44, a strain which has no plasmid. The smallest functional replicon was found to contain a single CDS (pE) and its flanking intergenic regions. Shuttle (S. citri/Escherichia coli) plasmids, in which CDS pE was disrupted, failed to replicate in S. citri, suggesting that PE is the replication protein of the S. citri plasmids. Successive propagations of pSci2-derived transformed spiroplasmas, in the absence of selection pressure, revealed that only pSci2 derivatives having an intact soj gene were stably maintained, indicating that the soj-encoded polypeptide is most likely involved in plasmid partitioning. Upon transformation, pSci2 derivatives, including shuttle (S. citri/E. coli) plasmids, were shown to replicate in all S. citri strains tested regardless of whether the strain possesses endogenous plasmids, such as strain GII3, or not, such as strain R8A2. In addition, the pSci replicons were introduced efficiently into the plant-pathogenic spiroplasmas Spiroplasma kunkelii and Spiroplasma phoeniceum, the transformation of which had never, to our knowledge, been described before. These studies show that, besides their implications for the biology of S. citri, the pSci plasmids hold considerable promise as vectors of general use for genetic studies of plant-pathogenic spiroplasmas. As an example, a HA-tagged S. citri protein was expressed in S. kunkelii. Detection of pE-hybridizing sequences in various group I spiroplasma species indicated that pE replicating plasmids were not restricted to the three plant-pathogenic spiroplasmas.
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Affiliation(s)
- Marc Breton
- Université de Bordeaux 2, UMR 1090 Génomique Diversité et Pouvoir Pathogène, F-33883 Villenave d'Ornon, France.,INRA, UMR 1090 Génomique Diversité et Pouvoir Pathogène, F-33883 Villenave d'Ornon, France
| | - Sybille Duret
- Université de Bordeaux 2, UMR 1090 Génomique Diversité et Pouvoir Pathogène, F-33883 Villenave d'Ornon, France.,INRA, UMR 1090 Génomique Diversité et Pouvoir Pathogène, F-33883 Villenave d'Ornon, France
| | - Nathalie Arricau-Bouvery
- Université de Bordeaux 2, UMR 1090 Génomique Diversité et Pouvoir Pathogène, F-33883 Villenave d'Ornon, France.,INRA, UMR 1090 Génomique Diversité et Pouvoir Pathogène, F-33883 Villenave d'Ornon, France
| | - Laure Béven
- Université de Bordeaux 2, UMR 1090 Génomique Diversité et Pouvoir Pathogène, F-33883 Villenave d'Ornon, France.,INRA, UMR 1090 Génomique Diversité et Pouvoir Pathogène, F-33883 Villenave d'Ornon, France
| | - Joël Renaudin
- Université de Bordeaux 2, UMR 1090 Génomique Diversité et Pouvoir Pathogène, F-33883 Villenave d'Ornon, France.,INRA, UMR 1090 Génomique Diversité et Pouvoir Pathogène, F-33883 Villenave d'Ornon, France
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